Natchez trace update

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Model T Ford Forum: Forum 2005: Natchez trace update
Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Sunday, February 10, 2008 - 09:41 pm:

Hi Folks Finally got around to finding the cause of the rearend failure. The drive shaft broke in two at the pinion bearing sleeve. The sleeve and pinion bearing both failed completely. They were after market of unidentified make and both pretty much disintagrated. The sleeve was in about 7-8 pcs. that we could identify as sleeve. The bearing was of the solid roller type, no spirals and it was in many pcs. also. It seems that cage pins that type of bearing is held together with were pretty much non-existant.(Ground Up) We will probably never know which went first,the sleeve or the bearing. We have many pictures to down load. We will send them along asap. The thrust bearing was Ford script and in very,very good condition. The pinion gear was in excellent shape and the ring gear from what I could see was also in very good condition. I will report on spider and other components as soon as I take it the rest of the way apart. More to follow BUD


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mack Jeffrey Cole on Sunday, February 10, 2008 - 10:01 pm:

Thank you sir for letting us know and keeping us posted as to what happened.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Sunday, February 10, 2008 - 11:06 pm:

Hey Bud:
Glad to hear Ginny and you are recovering well, and that the cause of this disaster is now coming to light. Sorry I wasn't able to attend the teardown today, as I have been detained in Mexico on business. As you and I discussed, I used these same style aftermarket non-spiral bearings at the 2 central axle positions only, and am now questioning whether that may have been a bad idea. I recently purchased a set of auxiary brakes, and am thoroughly convinced this was time and money well spent.
Best Regards,
Scott Rosenthal


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson on Monday, February 11, 2008 - 12:20 am:

Bud:

Thanks for posting the problem. A problem can happen to anyone at anytime. Do you remeber the Elk when we went over the top of Trail Ridge. Ben Hardeman took this picture. They were right along side the road.

elk


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Monday, February 11, 2008 - 05:11 am:

Hi Scott, Good to hear from you. Knowing what I know now, I would remove them and return them to who ever you obtained them from. If that's not possible send them to the scrap yard. No matter what they would be coming out of my unit. It would be easier now than after you lose a car because of them. My Fordor is too far gone to bring it back and it was a super machine. That junk was in it when I got it. I wasn't aware such stuff was on the market as I've always had enough good original nos and good used parts to support my T's. This is nothing new as Henry Ford himself fought that very problem, long,long ago. He called them spurious parts. Don't get me wrong here, there are some very good,very needed parts being made for our hobby. We need these parts to keep 'em rollin'.Think of this, Ginny and I lost a very good Model T which can and will be replaced,we are very lucky we weren't hurt worse or maybe killed!!! If it had rolled 1/4 turn more it would have been on top of her and with gas squirting thru the vent hole of that under seat tank all over inside where I ended up.( Fordors still had the tank under the seat.) I would have been a 275 lb. roast if it would have ignited while I was still in there. I was in there a while and three guys pulled me out thru the drivers window with that big fancy steering wheel in the way. The doors on a FORDOR are ver narrow and were jammed shut because the body was badly racked. I shudder to think what could have been a different ending. Too all; if you have some of that trash and can't return it, DESTROY IT so its out of the system for good. Doing so just might save your car and much,much more important YOUR LIFE!!! That's my thinking as well as those who helped shed some light on a very SERIOUS PROBLEM yesterday Feb.10th at RICK LONGHAUSER'S GARAGE. THANKS GUYS BUD SCUDDER


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Monday, February 11, 2008 - 10:04 am:

Morning Bud:
Does it look like you may be able to salvage any of the remaining chassis? I recall that was one fine running motor.
Regards,
Scott


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Monday, February 11, 2008 - 10:16 am:

Thanks for the info, Bud. This should be written up as a short article and posted on the front page, as well as sent to every local club for use in their newsletter.

Next time I run across some of those things I have in my spares inventory, I'll toss them. Better yet, maybe I'll take them back to where I bought them years ago. I remember a "friend" trying to sell me some of those at a swapmeet.

It has been known and repeated for up to 10 years on these Forums that the repro bearings and sleeves are junk, yet it took many years for hardened sleeves to become available.

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By Doug Menkhaus on Monday, February 11, 2008 - 02:00 pm:

I have lots of pictures from the tear-down...it shocked me to see that the failure in Bud's car was the exact same failure I had in my car in Marietta (only his drive shaft failed also). I will post the pics when I get home tonight. That engine must've been a real runner, as it literally twisted the drive shaft in half. (I have some close ups of the break)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Barker on Monday, February 11, 2008 - 02:23 pm:

I was more fortunate than Bud, but would certainly recommend NOT (repeat NOT) using the solid rollers and perhaps the modern inner sleeve.
Soon after I bought my '26 Coupe I had a failure of the pinition bearing sleeve. It rode up over the key it shares with the pinion and broke up. The pieces then caused the cage to break up and then something caught in the mesh and it lost a pinion tooth. The drive shaft was also scored.
The spiral rollers were actually OK.
Not knowing any better, I bought new-made parts - (solid) roller bearing, sleeve, drive shaft, key and a used pinion. 12 months later (about 1000 miles), something caused me to want to check it, if only to make sure the pinion was tight. The new sleeve had started to ride up over the key and had cracked. I think that the solid rollers don't 'give' as the drive shaft bends slightly. There is then very hard contact at the ends, and this causes the inner sleeve to 'walk' around the drive shaft. Fortunately, I caught things in time, and have now driven about 6500 miles with one of Lang's non-adjustable taper roller sets.
Incidentally, I phoned my order on a Monday afternoon and the bearing arrived at my home on Wednesday morning. Not unusual you say? Perhaps not- except that I live in Somerset in England!
Pity about the 17% UK import duty.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Walt Berdan on Monday, February 11, 2008 - 05:31 pm:

Bud,

Those bearings do sound like a weak link. Like you, I've always tried to find spiral wound bearings that are still in good shape. I will make sure I only use those or truly modern bearings in the future.

Was there any warning with this incident? Any sound, feel, or other symptom that in retrospect might have been a hint that something was going bad?

Walt


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Tomaso on Monday, February 11, 2008 - 07:37 pm:

I'm going to comment on the new inner d.s. roller bearing sleeves available - I have used dozens without a hitch ! I have seen many driveshafts worn down in this sleeve contact area and I truly don't believe there is ANY product available that will replace metal or permantly adhere the inner sleeve to a WORN out driveshaft. This is a MUST HAVE press-fit situation in order for the sleeve to stay where its at. I have quite a number of rebuilt rear axle/driveshaft assemblies running around the greater Seattle/Tacoma area and I won't use any driveshaft that is even marginal in this area as well as the pinion keyway area. If it isn't perfect - I won't & don't use it !


Top of pagePrevious messageNext messageBottom of page Link to this message  By warren rollins on Monday, February 11, 2008 - 08:05 pm:

As much as I would like to forget it ,I think this may be a good spot to retell our near disasterous accident of a few years ago.It happened on a T outing at night in hilly country in North Georgia. The rear axle broke and the iron emergency brakes naturally did not work as we gained speed going backward.Since it was dark there was no way to plan a reasonable stop. My wife at my instruction jumped out and I tried to wreck my T as quickly as possible. A drainage ditch stopped it with unbeleiveably no damage to the T.
No one was hurt. The cause was I strongly beleive the steel and leather seals that were introduced by Ford late in production. The sharpe springs acted as a saw to score the axle. It broke clean at this point. DON'T USE THESE.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Scherzer on Tuesday, February 12, 2008 - 01:08 am:

I thought I would post a picture of an original roller out of rear axle bearing and why they should be used over the solid type. A few years back I picked up a bag of these NOS loose rollers that were never put in a cage. Don't ask me how this came to be since I never heard of rebuilding them. In any case they make for a good demonstration for their need over the solid style.

When a new sleeve, a solid roller bearing and drive shalt or axles shaft are first assembled the bearing will roll parallel to the shaft but as wear starts and with these being a long bearing and mounted in a flimsy cage with loose fitting pinions holding the rollers they will start run cockeyed and finally to the point they will break and then as has been said " all hell breaks loose."
roller bearingroller bearing
With these original rollers they are able to flex due to the spiral forming of the roller. The first picture is of two straight ones but when clamped as I have done in the second picture you can see they are able to bend without breaking and return to straight again when released. Just noticed but the ones in the bag aren't rusty it just some old grease smeared on inside of the bag. If I ever get the time I plan to use these to rebuild some bearings by using them in old cages. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Tuesday, February 12, 2008 - 06:57 am:

Hi Bob and others Bob thats an excellent visual. At the "T" party we had Sunday Don Tyler And Myself were talking about how unforgiving the solid roller would be under anything but optimal alignment. Under any other conditions wear would occur almost from the git-go. This particular bearing and sleeve had seen at least 6 yrs. of service. Remember this is a heavy Fordor, with 8 days of luggage and all the rest of the stuff you need for a thousand plus miles in a week. It was being tested by a very strong engine and my driving style that pushes it to all of it's potential. The car ran 60 mph. with 4 passengers aboard many times. I was running Ford wire wheels, as good as any I've ever seen and new Firestone tires and tubes. I felt completely safe with this car. I can only guess that the sleeve and it's fit to the shaft was very good to take such a test for the Three yrs.,I have had it and at least three yrs.the previous owner drove it before I got it. He told me that rear axle had been re-built 3 plus years before I got it. I'm a retired class A machinist with tool making expierence and much heat treating and finish grinding time, plus the materials knowlege you pick-up plying that trade for 37 yrs. I understand press fits and the amount of interference required. I checked this bearng when I replaced the axel bearings and sleeves and could not feel any thing that would flash a warning. The pinion gear still looks very good only showing minimal wear patterns. (less wear marks than I expected). I only included this personal history to say I agree on the fit required to the drive shaft. Anything less would have failed a long time and many hard miles ago. I'm still of this opinion, find nos or good used Hyatt roller bearings and sleeves if your looking for safety and a good secure feeling about what your riding in. If you have any doubts about what your running, take it apart and inspect all components. BUD


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bruce Spainhower on Tuesday, February 12, 2008 - 01:44 pm:

Thanks Bud, for your thorough followup on your unfortunate event. I'm preparing my "new" '26 Fordor for my first season of touring, and about to tackle the rear axle and drive shaft, checking for wear and slop. I had already crossed the solid bearings off my list based on earlier posts in the forum.

I have a couple of questions. First, I can understand the need for the original flexible rollers in the axle, where the bending forces are obvious. But (and here's where I could use some advice from all those with exerience), is there really that much flexure in the drive shaft, and if so, wouldn't that also eliminate considering the modern rebuilt spools that use tapered roller bearings which also don't flex?

And second, I went back and re-read your October post describing your accident. Do you have any feel for whether the emergency brakes faded, failed mechanically, or were simply inadequate to the task? I've been hoping that I could rely on those "improved" 11" drums in an emergency.

Thanks,
- Bruce


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Tuesday, February 12, 2008 - 01:55 pm:

Bud:

I don't disagree that original design is very good but there isn't a good source for Hyatt type bearings for the Pinion Bearing which is why I made up my pinion bearing kit to replace the Hyatt with modern tapered bearing and sealed upper bearing. It is carefully designed and fitted and there are over 1200 of them in the field at this time on all sorts of cars. The qty in the field is NOT a statistic that guarantees success since if those cars are NOT driven that doesn't prove a thing but I just wanted you to know that I run this setup in my own car with over 40K actual miles on that bearing since it was first installed. I ran the Natchez trace with it in there too. I don't drive that car at speeds over 45 typically since it is not a speedster. Tony Verschoore did the motor and it is a strong runner. Most of my close friends are running our bearing kit and it was designed with close communication with Timken for confirmation of load life analysis. The truth is that the bearings in our kit were selected more for their dimensional need to replace existing bearings and install in existing housing than for load life since their load life is way longer than necessary for the actual application. A much smaller bearing could probably be used with success but the installation would be more difficult and costly into the existing pinion spool. We do NOT machine the actual spool on the early closed spools but insert a machined sleeve into the spool on those. For the later open spools we do machine them since the typical spool is worn egg shaped anyway and useless for actual stock use anymore. Once machined by us, those later spools could be rebuilt again and again by inserting new bearings inside if needed. I believe that our pinion bearing kit is safe as designed and I have one for my son's car and Tony Verschoore has one in his 1912 touring for many years and that car does go 70 MPH actual tested.

I think that folks need to check very carefully what they are buying since I know one vendor changed his axle bearing sleeves to say they were "hardened" when they were the same old sleeves just sent out to be hardened and NOT of the new sleeve design which Steve Coniff pioneered with research into Ford archival material. Make sure the vendor knows what he is selling and make sure you get the GOOD hardened sleeves to go with your original Hyatt bearings and that is a good setup.


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Tuesday, February 12, 2008 - 05:40 pm:

Hi John, I have never used either yours or Steve's bearing components. Knowing you both and your excellent product integrity I would never question their quality or the research that went into manufacturing them. My remarks were directed at the very junk that caused my problems. I apologize if I came across in a manner to suggest anything different than that. I would be very willing to use either your's or Steve's parts. I get around the hobby quite a bit, but never have heard of the successful numbers you just made me aware of. I stand corrected. I am very glad to hear these very necessary parts are available again. This information is a very powerful reason that this forum is so valuable to us all. I can tell you now,if I would have been aware of their availability they most likely would have been in my car. I never had any rear end trouble to amount to anything because I always had plenty of nos and good used parts to do my cars. They are however becoming more scarce by the day. We need all the quality parts we can get our grubby paws on!!!Best Regards BUD


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Tuesday, February 12, 2008 - 08:47 pm:

Bud:

No apology necessary at all. I understood the direction of your information. I simply wanted to calm down any folks who might be using the Fun Projects kits and might be wondering if I had a skeleton in my closet - I don't. Those solid bearings just seem to be a very bad idea. I notice that many dealers catalogs state clearly they are NOT to be used on cars that are driven very much. The problem with that disclaimer is that nothing prevents the thing that happened to you - namely - you purchase a car and drive it assuming that the rebuilt rear end is good to go. Suppose also that someone uses those bearings in a car built for a museum - OK so all is fine until somebody comes along and decides they want the museum car and want to drive it - is anybody going to be there to inform that buyer that the bearings in the car are dangerous?? Not likely. How many museum cars or barn pulls come with complete documentation as to what is under the paint? For what its worth - the reason I designed the pinion kit in the first place was that I bought another one on the market at the time and it failed on the way to the FIRST Iowa MTFCI tour (not the most recent one). I got about 45 miles down the road and it got hot and seized up. After a more careful analysis of the thing it was obvious why it seized so I built my own and made a few copies for local chapter members and the rest is academic.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Tuesday, February 12, 2008 - 09:14 pm:

John Regan:
I recently rebuilt a rearend using your Timken retro driveshaft assy, original spiraled outer axle bearings outboard with hardened sleeves, and the new solid roller bearings with hardened sleeves at the 2 inboard positions. In your opinion, is there a tangible risk assuming moderate use of this equipment? When I selected these components, I had been informed by multiple vetran T enthusists that this application was proven sound...now a bit concerned. Much happreciation for your thoughts and comments.
Regards
Scott


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Tuesday, February 12, 2008 - 11:40 pm:

I'm with Bud on this one - take it apart and toss those things. I have heard just one too many horror stories on those things. They are simply a bad idea. My personal belief is that because they cannot flex at all there is enormous weight and wear at the point where they spin in the cage. Regular Hyatt bearings don't have a stress point there because the roller isn't stiff. I wonder if Bud might wade back in and verify if indeed some of the rollers appear to have come out of the cage or broken off at that point. That is the issue that is there regardless of the installation precision. I just would NOT trust those things at all since you are using them in a design that was put together for the Hyatt bearing. If somebody didn't know enough to think those solid bearings through when they designed it - how does it make you feel about the rest of their ability to knowing when/where to use it. Did they know anything about metalurgy and hardening? Do you want to risk your 1913 rear end housing and passengers? Sorry to be the bearer of bad news but if I were you - I would count myself lucky that I got a chance to preview a possible problem BEFORE disaster strikes. I am sure Bud would love to have known what you now know beforehand. If you decide to proceed and "chance" it - you are really going to hate yourself if something bad happens.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Wednesday, February 13, 2008 - 02:58 am:

Many thanks again John and Bud. Really would like to hear from suppliers and regular drivers who have been running these bearings installed as I've described...especially those who have been running them for significant durations. I'm very much concerned that the especially credible supplier I purchased these from represented them as reliable when used for the inner axle application only. It is my understanding that these have been sold and used in regular drivers for quite some time now, and that there are significant numbers of operational cars running them now. So far as I have been able to determine, no supplier recommends this style bearing for the pinion application in a car that is to be regularly driven.
Regards,
Scott Rosenthal


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Wednesday, February 13, 2008 - 03:06 am:

Hello Scott, Haven't gotten into it any deeper than pulling the drive shaft which gave up the needed info as to what failed. If I understand your question correctly you are unsure of the solid type roller axle bearings you installed at the inboard area of the axel housings. If they were in mine they would be nice and warm from the speed at which they would be coming out!!! NOW, the pinion bearing cage was totally apart. All rollers were out and very little of the cage was found, one end plate and 1-1/2 of the pins that form the cage was all we were able to find. There will be some very explicit photo's available to this forum soon. There were four cameras present and all photos are not yet ready. You will be surprised at the story they hold. You can also get some input from Royce Peterson as he witnessed the total failure of the solid roller type axel bearings as well the sleeves, in that same rear end, he and I worked on several years back. BUD


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce on Wednesday, February 13, 2008 - 06:19 am:

I would not even have one of those solid roller bearings under the seat of one of my cars. They are JUNK. Your life and your family's lives are too valuable to risk on something like this Scott.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mack Jeffrey Cole on Wednesday, February 13, 2008 - 07:12 am:

Why are'nt the orignal bearings being reproduced?I cant help but ask that question.
Small market,but each T owner would be buying 1 set per car probably in our life times,so this is 1 of those things that isnt a bad investment would be a decent set of bearings made for the application.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James A. Golden on Wednesday, February 13, 2008 - 10:00 am:

Now that Bud has identifed his problem, I am amazed at the number of people that are telling me, "I had that same problem or my friend had that same problem!"

These are all people with many years Model T mechanic and machinist experience, along with excellent track records.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kirk Peterson on Wednesday, February 13, 2008 - 11:19 am:

I am fairly new to the Model T hobby. For future reference, what is the part number of the bearing that failed?

Thanks
Kirk Peterson
Santa Fe, NM


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Scherzer on Wednesday, February 13, 2008 - 11:31 am:

Reproducing a unique roller like this I believe is a lost art or just too hard to reproduce correctly and if you could find a company willing to make a job run the expensive of doing so would be out of the question price wise so that in the end you would wind up with an affordable yet correctly made replacement. Just look at Timken dropping the T front bearings due lack of sales and they already have the machinery in place to make them if they chose to.

I think what John have designed as a replacement for the drive shaft bearing is probably a lot better and at an affordable price range then going back and trying to reproduce these original rollers. Bob.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mack Jeffrey Cole on Wednesday, February 13, 2008 - 12:04 pm:

Not wanting to hijack but gota ask,timken has dropped the front wheel bearing after all these years? Crap,who will we get them from now?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Doug Menkhaus on Thursday, February 14, 2008 - 12:41 am:

Hi everybody, sorry for the delay..I know I promised pics of the tear down, but I got tied up, and now I can't find them on my camera?
I want to mention that I've been following this thread with GREAT interest since it started. Please PAY ATTENTION to this thread! It's not hard to fix your T in your garage. Henry made sure everybody could do it. I rebuilt my reat end using the reproduction parts available at the time (~6 years ago) not knowing much about Model T's. I sent a picture to a vendor (no longer in business, but NOT do to anything related to the Model T's) and asked him to send me everything available to rebuild my rear end. I ended up with SOLID ROLLER PINION BEARINGS for the drive shaft, along with the same solid roller bearings for the axles.
About 1000 miles later, after the rebuild, I was in Marietta, OH for the annual All-Ohio Jamboree, driving the first day (in the rain!) when my T started to randomly JERK really hard. Every few miles, it would JERK really hard. Just before lunch, to the dismay and disappointment to my wife, I called the Vulture wagon, more for fear of breaking something than anything else. Later that first night, everybody gathered in the parking lot of the hotel to try to see what was the matter. We pulled the rear wheels, spund everything a couple times, even drove it behind the local Wal-Mart, but couldn't get it to JERK like it did that day. I was convinced to give it another go the next day.
The first hill we encountered told me I was wrong. I couldn't get up the first little hill in low gear, I just didn't have enough engine to do it. I backed down slowly (remembering that my new Rocky Mountains didn't work in reverse) and called the vulture wagon again. We were done for the tour.
Later, back home, I tore apart my rear end. HOLY COW! What were those parts coming out of the rear end?! Big Metal Parts!
It was later determined (at a club rebuild session) that the drive shaft pinion bearing (the solid roller type that I had used during the rebuild) has failed. The picture attached shows that multiple peices of the pinion bearing actually made it through the ring and pinion gears! That explained the JERKING! I later replaced the Pinion bearing with a FUN PROJECTS bearing, and also replaced the axles, and the Axle bearings with all new modern assemblies. (YES, they were EXPENSIVE! PLEASE PLEASE PLEASE DO NOT TELL MY WIFE HOW MUCH THAT REAR END REBUILD COST!-> I decided it was MUCH better to spend the money than to slide through a STOP sign!)
The pinion bearing I had came out in pieces! The cage had failed, the drive shaft sleeve was disintigrated, and the pieces were in my axle. Luckily, I stopped for fear of breaking anything.
I posted pics of the pieces that came out of my rear-end last year about this time. I had no idea at the time the magnitude of the problem.
In my UN-PROFESSIONAL, NON-ENGINEER, EXTREMELY BIASED OPINION, I have the following OBSERVATION->
As we all know, Henry's Hyatt bearing is a spiral wrapped cylinder that (a) flexes with rotation, and (b) has grooves that allow for oil penetration. The replacement bearing rollers are SOLID, and have no grooves.
Given that the replacement rollers are solid, there is no flex to the set-up. Picture This: You have a 1 inch thick metal rod/bar that is the drive shaft. You have 1/2" thick metal rollers that are the roller bearings. The sleeve between the two is about 2mm thick. The weak part of the equation is the sleeve. If anything is going to fail..wouldn't it be the sleeve?
Look at the pictures of the failure in my rear end. The sleeve is in multiple pieces. It is my un-educated, un-trained, non-engineer opinion that the non-flexible roller-style bearing's continually beat upon the sleeve to the point of failure, causing the destruction of the pinion bearing assembly.

Thought? Opinions?

This came out of MY rear-end, not Bud Scudders...


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Thursday, February 14, 2008 - 01:29 am:

I have only a few thoughts here and I could be way off base but I would carefully measure the DIAMETER of the ENDS of the rollers where they are protruding into the cage. In all pictures I have seen, those ends appear to be worn down or gone. When something breaks, WEAR ACTUALLY STOPS instantly and crumbling starts so even though twisted up you can measure that end diameter versus a new one and my guess is that those things wear big time on the ends and eventually one of the ends lets go and then a roller gets cocked sideways and BANG!! Sure the sleeve will go at that point too but if the sleeve was just wearing away methinks it would HOWL to beat hell and you would hear it. Those small ends on the other hand might wear completely off without much noise until one was gone. Like I said to start - I am just guessing here based on pictures I have seen. The whole idea of the solid roller with no oiling system built in is scarey enough for me and I sure don't want to be quoted as suggesting these things are OK if they were built more carefully. It is just the detective in me that wants to find out the whole story.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Thursday, February 14, 2008 - 02:30 pm:

I've been researching this with a number of known and respected local and national resources, and while certainly not conclusive, these comments continue to float to the top. First that the solid roller pinion bearing application is doomed to a premature failure for at least two obviuous reasons (This info is nothing new and no vendor selling these parts will argue these points). The solid rollers do not churn the grease lube as do the grooved style, but tend to isolate themselves from the especially viscous paste. The pinion bearing endures both side and thrust loading, as the result of the pinion gear being forced apart from the ring gear under load. This condition agreed, even the original style grooved bearing application is extremely challenged. Many have inspected these original bearing assemblies to have found that the sleeves are cracked and/or distorted. The J. Regan Timken bearing retrofit effectively targets these two conditions while also offering significantly improved and maintained positioning of the pinion gear realtive to the ring gear. It is fair to conclude that this improved wear consistency also translates into the generation of less heat. Conversely, the axle roller bearings see no thrust load. The two inner axle roller bearings see the least abuse of all 5 rearend roller bearing locations, as they act as little more than minimal load alignment guides. Couple this with the fact that these bearing locations are gear oil flooded, resulting in positive lubrication. The outboard roller bearing like the pinion roller bearing, is grease lubed and manages extreme shock loads transfered directly from the rear wheels. Also like the pinion roller bearing, the solid rollers and centrifugal force will push the heavy grease away from this bearing, versus churning it. For these reasons and likely others, solid roller bearings at the outboard axle positions are on borrowed time from the point of installation (This is also know and agreed to by all of the solid roller vendors I spoke with). These factors considered, I am inclined to believe that a solid roller bearing replacement of the inner axle bearings does not pose the same high risk potential of either the pinion or outbord axle applications. Knowing what I do today however, I would have installed the original style grooved bearings at the center axle positions, only because they apparently will ultimately last longer. Many thanks again to Royce for encouraging me to also install accessory brakes on my project. These are a simple and inexpessive precaution that greatly improves protection to the car and it's passengers, and to potentially other drivers.


Top of pagePrevious messageNext messageBottom of page Link to this message  By RDupree on Thursday, February 14, 2008 - 09:45 pm:

How about letting another retired engineer chime in? My believ is that the spiral design has nothing to do with lubrication. If so, why not spirals in the front wheel bearings? The Chevy mid and full size passenger cars of the 70's and 80's used a SHORT solid roller design that seemed to last quite a while with just a minimal amount of differential grease that happened to slop into the area.

I think John R has the clue. The key to the success of the spiral wound bearing is its ability to tolerate angular misalignment of the inner and outer races. Think about it...How many degrees of misalignment will it take to wind up with point contact between the corner of the bearing and its race. Then think about the probable deflections occuring in the rear axle as you bump along the road, or the runout on that ancient driveshaft you are using. The failure scenario remains point contact of the bearing ends, leading to failure of the 'weakest' part, either the axle shaft, or the differential bearing.

Back to the lube theory. Did you ever try to figure out what is actually inside the spirals of an old wheel bearing. Metal chips. Lots and lots of metal chips. I wind up using a combination of ultrasonic cleaner in conjunction with putting the bearing in a paint can full of solvent and letting it shake on the paint shaker for a while. You will be amazed at the amount of iron that comes out.

By the way, I have one of John R's pinion bearing kits for the diff I am building now.

Ron Dupree


Top of pagePrevious messageNext messageBottom of page Link to this message  By RDupree on Thursday, February 14, 2008 - 09:48 pm:

How about letting another retired engineer chime in? My believ is that the spiral design has nothing to do with lubrication. If so, why not spirals in the front wheel bearings? The Chevy mid and full size passenger cars of the 70's and 80's used a SHORT solid roller design that seemed to last quite a while with just a minimal amount of differential grease that happened to slop into the area.

I think John R has the clue. The key to the success of the spiral wound bearing is its ability to tolerate angular misalignment of the inner and outer races. Think about it...How many degrees of misalignment will it take to wind up with point contact between the corner of the bearing and its race. Then think about the probable deflections occuring in the rear axle as you bump along the road, or the runout on that ancient driveshaft you are using. The failure scenario remains point contact of the bearing ends, leading to failure of the 'weakest' part, either the axle shaft, or the differential bearing.

Back to the lube theory. Did you ever try to figure out what is actually inside the spirals of an old wheel bearing. Metal chips. Lots and lots of metal chips. I wind up using a combination of ultrasonic cleaner in conjunction with putting the bearing in a paint can full of solvent and letting it shake on the paint shaker for a while. You will be amazed at the amount of iron that comes out.

By the way, I have one of John R's pinion bearing kits for the diff I am building now.

Ron Dupree


Top of pagePrevious messageNext messageBottom of page Link to this message  By Luke Chennell on Friday, February 15, 2008 - 12:01 am:

I had an interesting experience a while back. We tore down a Ruckstell that had a cracked outer keyway on an axle to fix the axle (a Ford axle that measured 1.062" - pity to see that destruction), and in the process found that the inner bearing hadn't been installed on the Ford side during the rebuild. The car in question had a RAJO overhead, 3:1 gears and had seen about 1000-1500 miles of fairly hard, high speed touring. The ring and pinion showed no sign of undue wear.

Of course, I would NEVER reccomend assembling an axle without the inner bearings, but I have to admit that it was something of an eye-opener for me to see how well this rear axle performed with one of the major components completely missing. Of course, the Ruckstell side ball bearing does a significantly better job of absorbing the thrust and radial loads than the Ford combination Hyatt-babbit thrust washer ever could, but the result remains.

Would I use a solid roller inner bearing? Nope. I've never put one of those together, and in fact I've thrown out a lot of them. Too many failures and such a bad rap that I'd never use one. Reasonably good original Hyatts are around if you're willing to look. Myself, I use the best ones on the inner (.498" or more) to make sure the ring-and-pinion mesh is maintained, and use my worser ones (.495" to .498") on the outers, as they're both easily replaced and won't tear up gears that way. But that's just my theory. Yours may vary. And, as Stan Howe says, probably should.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Friday, February 15, 2008 - 11:11 am:

Scott,

You've given the solid inner bearings issue some very careful thought and consideration and made some excellent points. That being said, I would REMOVE THEM IMMEDIATELY. It's very easy to come up with reasons not to do what you ultimatly know is best. You even stated that you wouldn't do it again, so you know it's not the best choice.

You're correct in that those inner bearings don't see the same load as the outer ones, but have you considered the extreme load, although periodic, during heavy braking? What about long hill climbs? We already know the solid rollers are not sufficient for pinions & outer bearings. How close are they to being insufficient for inner bearings? Where is your margin of safety?

Also consider this. The solid pinion bearing, which is known to fail, transmits probably 75% of its loading to the ring gear side, inner bearing. (75% is a guess-timate and based on the ring gear being located considerably closer the one bearing over the other.) So, if 100% of the applied load makes a solid pinion bearing fail, what will 75% of the load do to a solid inner bearing? Consider also that the pinion bearing has larger diameter rollers to begin with.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Friday, February 15, 2008 - 12:03 pm:

I have said my piece with regard to whether these solid roller devices should be used anyplace but I think it bears pointing out that it has NOT been proven that LOAD is what is causing these things to fail catastrophically. While the natural assumption with a real bearing is that it will most likely fail under load - it should be pointed out that these things are NOT designed to any BEARING specification that I am aware of so in my mind assuming they will fail like any bearing eventually fails is perhaps a dangerous assumption that I for one am not willing to make. It could be a failure related to alignment of the rollers within the cage, a failure due to incorrect metallurgy and/or hardening, a failure due to lack of lubrication ability or simply a failure by design concept of how these devices might replace a hyatt bearing in a given application. I don't feel comfortable that the failure mode has been exactly identified enough to say just what sort of operation of these devices is indeed OK.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe on Friday, February 15, 2008 - 12:14 pm:

I think everything here has been covered but I want to make one point based on what I found out last year when I was rebuilding three Ruckstells for delivery at Chickasha. The "hardened" sleeves available from a couple suppliers are not the correct thickness. They may be hardened or not - I have no way to check that - and they look to be heat treated as they are a dark blue color. But they are not as THICK as the original Ford sleeves or the quality ones available. I ended up buying about a dozen from Lang's and having them next day air shipped to me after I measured the colored ones, having spent an hour or two trying to figure out why the bearings were not tight in the new sleeves I had installed, considering that I had also installed new axles in two of the Ruckstells. If I recall correctly the new "hardened" sleeves were .0600 and the top quality ones were .0675. I believe the quality ones are the ones that Steve Coniff and some others developed. I don't know if he manufacturers them or not but they are available from Langs and Snyders and I'm sure, from others. Fifteen thousanths total section is a lot when you figure that you are trying to find bearings within a five thousanths range. The difference in cost for a full rebuild is less than $50 if you replace all four. I would never do another diffie -- either standard or Ruckstell -- without replacing the sleeves with the new quality hardened sleeves unless I had good originals. A Ruckstell, of course, only takes three roller bearings and sleeves as the main support, alignment and thrust is taken by the ball bearing on the Ruckstell side.

I have also been using John's roller bearings for the pinion. I thought about making an improved model and going into competition with him but I couldn't see any way to improve it so I'm foiled again. I did make up a set of simple specialty tools to aid in fitting the pinion/ring gear clearance and for preloading the bearing, which is necessary IMHO for long life of a tapered roller bearing. It is also fair to say that the standard pinion setup has run for billions of miles in the last 80 years and many people do not believe the roller conversion is necessary. I agree, IF you have good original bearings and a good sleeve. It is pretty cheap insurance tho, putting in the roller conversion and makes it much easier to set the r/p clearance correctly.

As an additional aside, there should be NO differential rebuilt and put back in service that has not had the housings checked for correct alignment. Many are bent from years of rough service and need to be straightened so there is not constant pressure on the bearings, sleeves and axles as well as the axles gears, etc. The driveshaft should be checked for alignment to the differential cases also as many of them are bent out of alignment.

I believe you should be able to put an axle nut on and turn the whole assembly with a box end wrench by hand when you get it all rebuilt and not have excessive drag or you have it set up too tight or something is binding due to bent housings, etc. I don't beieve in expecting things to "wear in." The exception to this is if you are using an original fibre washer in a Ruckstell rebuilt -- which hardly anyone does -- there will be more drag.

As always, this is my opinion based on 54 years of fooling with Henry's Finest Creation. I am not an engineer, have no metalurgy training etc., and am not trying to sell anything so your experience and opinions may, will and probably should, vary.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Friday, February 15, 2008 - 12:35 pm:

Morning Jerry:
The percieved longevity issue is the reason I would option for original bearings if conducting another rebuild. You make excellent points, all with merit IMO. I'm now aware of two especially well know performance T's that have been running these without issue for quite some time, and I'm told that current T's numbering in at least the hundreds are successfully running them as recommended also. Consider also that my particular project (12 Town Car)will not be driven heavily and will unlikely see hill climbs, 2000 mile tours, etc. My opinion at this point remains that these bearings are fine when used as recommended in moderate use applications. I'm accutely aware that we're in most cases dealing with parts that are close to 100 years old. I sense an indirect conclusion being implied by some comments that "when you rebuild with original parts, failures are not likey to occur". You'll agree that these perceptions exist, and may also represent a safety threat by contributing to a false sense of security. Per this thread, I have requested testimonials specifically from those who have used these bearings as recommended and experienced inner bearing failures. I'm still anxious to hear these responses, and am by no means convinced that this has not occurred, simply because those accounts have not been presented here. I'm very much encouraged that this discussion continues to yield valid facts, first hand accounts, and worthy opinions. If the conclusion at the end of the day is that these bearings are a tanible risk, then I will remove them. If not, then let's cut the manufacturer and suppliers some slack. None of these guys would put themselves, their family menbers, or their customers in harms way, knowing that a defective product poses an unreasonable risk. Bud's accident has renewed a necessary awareness of this potential risk that is clearly being taken seriously. I'm much impressed that these responses have been solid on substance with no time wasted on B.S.
Regards,
Scott Rosenthal


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Saturday, February 16, 2008 - 12:54 pm:

Here's a photo, more to come


pic1


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Scudder on Sunday, February 17, 2008 - 01:02 pm:

Here's another pic of the rear-end failure..


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Sunday, February 17, 2008 - 05:31 pm:

more pics of the failed rear end

failed rear end


Top of pagePrevious messageNext messageBottom of page Link to this message  By Doug Menkhaus on Sunday, February 17, 2008 - 05:32 pm:

Here are some spare parts


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Sunday, February 17, 2008 - 05:44 pm:

picture of failed rear end


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Sunday, February 17, 2008 - 06:04 pm:

more pictures


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mack Jeffrey Cole on Sunday, February 17, 2008 - 08:37 pm:

Scott,here is 1 point to consider.You explained your 12 town car is expected to live a light, easy life without alot of hills,etc.But lets say 3 to 5 years from now selling this car becomes nessasary and that buyer is fiqureing on makeing it a driver.The questionable bearings may fail during his use with unknown end results.
I must say,I would hate to buy a nice T,and have to tear it apart to make sure it had safe bearings in it,when it coulda had them installed during the recent overhaul.


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Sunday, February 17, 2008 - 10:08 pm:

Hi Folks I have a lot of pictures to go,but I can't get the hang of posting them,soooo I'll try some more tomorrow.The pictures that are posted pretty much explain the failed components. The brake parts are there to show that it had darn good brakes. The lining that seems to be worn more on one side came from the right side and I'm guessing that happened when the Ford laid over on the passenger side. Remember I had that lever pulled back as hard as possible and it was dry inside the drums. It laid on the passnger side about one hour and no grease leaked out.Some pics
have the wrong title and I'll try to correct that .


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Monday, February 18, 2008 - 12:53 am:

Mack Jeffery:
A true enough scenario given that this is exactly what happened to our good friend Bud. Being the consciencious person that I am, I will disclose the origin of all components as these descriptions are also contained in multiple folders of documentation I have compiled while building this car from pieces. I'd like to believe that you the many good and honorable T people I have come to know in this hobby would do much the same. There are of course a number of other goodies hidden under my baby's hood that I would likewise be ablidged to disclose. Indeed, many such mechanical updates represent some level of risk, and you'll agree that the ubiquitous T is not a toy for the faint of heart. My advice to anyone purchasing not just a T, but any early automobile they would want to drive that is of unknown mechanical history...Pay the money and have this vehicle thoroughly inspected by only a qualified mechanic. Per Stan's comment pertaining to pre-assembly housing inspections...absolutely! This apparently common defect in my opinion has excellent potential to result in bearing failure, regardless of which bearings you use. If you have a clamshell rearend...check the housings twice.


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Monday, February 18, 2008 - 08:15 am:

Pinion Gear

The picture of the pinion was posted to show that it absolutely did not fail in any way that I can see with the naked eye. I have no way of knowing, with out a magna-flux check, if there are any hidden cracks. After the check,if any thing negative shows, I'll post it. I do not know who made this gear. I will re-use this gear if it checks out o.k.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Pawelek on Monday, February 18, 2008 - 12:10 pm:

"Pay the money and have this vehicle thoroughly inspected by only a qualified mechanic."

Scott, Would you please list all the the "qualified mechanics" you know that are familiar with pre-1930 automobiles that I could contact to inspect before I buy it? I would venture a guess that 90% of modern trained mechanics wouldn't have the slightest idea what to inspect or look for that is dangerous in the Model T transmission or differential much less even know how to start and drive the vehicle. From my point of view it's buyer beware. Anyone who buys a vintage car would be wise to study up and check these area on his own. Besides that no seller would let a stranger take apart the diffrential before the sale, at least no one I've ever met! :-)....Michael Pawelek


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Monday, February 18, 2008 - 12:26 pm:

Agreed, Michael. Not only that, what about the second buyer?

These things should all be sent back to the vendors, and the vendors should be prohibited from further ads in VF until the things are removed from stock, and a warning put in their catalogs.

That's a good way to stop trafficking in dangerous goods.

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Hood on Monday, February 18, 2008 - 02:59 pm:

All of this discussion seems to be centering around the bearing, but the pictures show that the sleeve is completely destroyed and in many pieces. Is it possible that the sleeve is failing first? Just asking.


Top of pagePrevious messageNext messageBottom of page Link to this message  By bud scudder on Monday, February 18, 2008 - 04:09 pm:

Hi Jeff That's the same question I asked and John Regan thinks that maybe the bearing rollers went first because some of the small diameter stubs on these rollers have been found to be missing. See above post.Not just on mine(the pictures plainly show they are not there)but, also on other known failures. That would indicate those rollers could move out of alignment easily and to me all heck would break loose. This by NO means IS conclusive. I hope an absolute, proven cause will surface so as to end this problem.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Hood on Monday, February 18, 2008 - 05:56 pm:

I see that the stubs are missing, but once the sleeve pieces started jamming themselves between the bearing rollers, the stubs wouldn't stand a chance! If the bearing failed, I'm not sure that it would cause total disintegration of the sleeve. I think that it might be badly damaged, but shouldn't it still be in one piece?


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Monday, February 18, 2008 - 09:14 pm:

I wish to clarify that I BY NO MEANS am saying that the solid roller device WAS the thing that failed first. The case is NOT totally proven by any means. I think I also stated that it is entirely possible that the load on these things has nothing to do with the failure mode either. We just don't know for sure but it doesn't take much imagination to understand what would happen if those ends DID wear off and let those rollers loose. The track record of these solid roller devices will tell the tale. I have NOT heard of continuing reports of original bearings failing this way and they use the same sleeves don't they? The problem is that the original pedigree of all the parts in question is unknown. At this point one can only speculate until enough failures occur to make it obvious whether these solid roller things are the source of the problem or the victim. If the sleeves are the problem, they will fail like this with original Hyatt roller bearings too won't they? I don't feel the case is totally proven but I would be less than honest if I said I didn't have my suspicions.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Tuesday, February 19, 2008 - 05:10 pm:

A guy in our chapter began to notice some rear end noise and took things apart to inspect. Everything was o.k. except that the drive shaft sleeve looked as if it had begun to rotate on the shaft and in doing so, began to break out where it engaged with the pinion key. The broken area of the sleeve ruined his hyatt bearings. In his case, the sleeve was definetly the cause of trouble. The odd thing was that the sleeve was still hard to remove and still had what seemed like a good press fit.


Top of pagePrevious messageNext messageBottom of page Link to this message  By gord rolfe on Tuesday, February 19, 2008 - 10:01 pm:

should i replace the 2 outer sleeves for the rear axles that i installed earlier as replacements for the worn out sleeves? i am using the original 5 hyatt bearings as well as the 3 other sleeves.the 2 outer sleeves measure 0.061 inches thick.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott rosenthal on Wednesday, February 20, 2008 - 11:34 am:

Michael:
No...you sure won't find this service at Jiffylube. I rebuilt my rearend myself, after researched materials and proceedures with a handful of the T faithful here in the Nokin T's Club of Cincinnati, along with the excellent resources at Ron's Machine, Chaffin's and Lang's. The info is out there, it's easy to get, and it's free for the asking. If you cannot or don't wish to turn wrenches yourself, there are no shortages of those who will gladly do it for you for a fee, with you supervising and providing the technical data. If you want to drop your car off with someone who will do all the research and do all the work, they're are no shortages of resto shops out there...look in Hemmings...They're definitely listed, and they're definitely interested. One only needs to be prepared to pay their price.
Regards,
Scott Rosenthal


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Barker on Wednesday, February 20, 2008 - 04:06 pm:

I posted some information on the two failures in my car earlier in this thread, but John Regan says he is looking for further evidence to show how these bearing failures start and develop.
I am one of those people who don’t throw things away, so I have been able to go and find the pieces I removed on both occasions, make some measurements and take some photos.
The first failure occurred with the standard Ford parts – I don’t know what had been replaced earlier in the car’s life but the axle still had white metal thrust washers and spiral rollers in all locations. I had no symptoms before a sudden harsh vibration which must have started when the pinion lost a tooth – and this was caused, I’m sure, by a piece of inner sleeve becoming trapped in the mesh. The parts are shown in the first photo with the broken pinion. Here are some dimensions (inches):
Rollers diameter: Engine end (undamaged) 0.556 to 0.558
Pinion end (damaged) typically 0.540
Sleeve OD Approx 1.25 but it is cracked lengthways
Sleeve length 2.6 maximum – it should be about 3.06!
Cage end ID Engine end (undamaged) 1.29
Pinion end (damaged) 1.30
I am sure that the failure originated with the sleeve riding up over the key. All the damage is at this end of the bearing. The cage ID has been increased by the swollen sleeve before bits started to break off. The pinion was in good condition, with some evidence of pitting on the braking faces – also present on the crown wheel (still in service today). The rest of the axle was fine, but I fitted bronze washers and new outer shaft sleeves.

The drive shaft was also scored in the sleeve area. The outer spool seemed to be fine, as was the thrust bearing – see below. I installed a new inner sleeve, drive shaft and (solid) roller bearing, together with a used pinion. The new sleeve was a tight (hammer) fit on the new drive shaft.

About one year and perhaps 1000 miles later something made me go and check things. What I found is shown in the other photos. The new sleeve had ridden up over the keyway in the new shaft and worn the ID of the roller cage. The sleeve had rotated as if the rollers had ‘pushed’ it round. Fortunately, nothing had broken away but failure wasn’t far off. The rollers had obviously resisted the deformation – there is a definite ‘joggle’ in the sleeve where the area under the rollers has been held in shape whereas the free end has deflected. The cage is intact, though worn on the pinion end ID by the swollen inner sleeve. The sleeve (undamaged part) and bearing are still a good fit in the outer spool – as shown by the dimensions below:
Rollers diameter 0.562 everywhere. Some marking at the ends near the pinion.
Sleeve OD 1.248
ID 0.999
Length 3.06
Cage end ID 1.313 – engine end, undamaged
1.408 – pinion end, worn away by sleeve riding up over the key
Outer spool 2.372- engine end
2.375 – pinion end – some scoring
2 x the roller diameter plus the sleeve OD is 2.372 – the same as the spool ID.

I did some calculations relating to the interface between the inner sleeve and the drive shaft. Under load, the shaft will twist and bend under torque.
The torque effect is quite easy to calculate (with the aid of one of my university text books).
For the drive case, the maximum engine torque is about 80 lb.ft, but the shaft could see 50% more if the low pedal is ‘stamped on’ with the engine running fast. Low gear is just over 3:1, so the maximum instantaneous drive torque is about 375 lb.ft.
For the braking case, I suggest that if you manage to lock the rear wheels on a good surface, you will get about 0.4G deceleration. So if the car weighs 2000lb, that will be 800lb at the tyre surface. With 15” radius and standard 11/40 gears, that makes 275 lb.ft on the drive shaft in the opposite direction.
Applying 375 lb.ft torque to the 1” shaft, over the 3.06” long inner sleeve there will be a wind-up of about 0.65 degrees, which is about 0.006” round the shaft at its surface. The sleeve is about 15 times stiffer in torsion than the shaft so there must be movement. The brake torque will result in relative motion of about 0.004” in the opposite direction. So the shaft and sleeve will ‘fret’, at least when subject to the highest loads.
The torque in the shaft arises because of the contact at the pinion teeth. Contact occurs at about 1” radius, so there is also a sideways/bending load of up to 4500lb on the shaft and bearing. It’s hard to determine exactly how the bearing will resist this but you can be sure that the loads are highest close to the pinion, especially with the solid rollers which will not bend or ‘squash’. The relative motion between shaft and sleeve caused by bending could be of a similar magnitude to the twist effect – and remember that this deflection rotates with the shaft, unlike the wind-up.

To summarise; the evidence shows that for my two failures, which occurred with different shafts, sleeves and rollers, the failures both originated because the sleeve was forced round the shaft so that it over-rode the key. The deflections of the shaft under load make it possible for the sleeve to move, and I suggest that the solid rollers result in concentrated loads near the pinion which push the sleeve round. The fit of the second shaft/sleeve assembly was fine, but I have no way of knowing the tightness of fit of the first sleeve on its shaft, or if the key and sleeve met with square faces. Clearly, most Model Ts manage fine with Ford’s original spiral rollers. However, I’m staying with the modern taper rollers!
First failure - spiral rollersSecond failure - solid rollersSecond failure - solid rollers. Damaged sleeve


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Wednesday, February 20, 2008 - 04:48 pm:

Good analysis, Chris.

Minor correction: Low is 2.75:1, not over 3:1.

If engine torque is moving the inner sleeve, I would expect its movement to be in opposite direct to what is seen in the lower pix. Maybe that damage is from tranny braking? A sudden stab of the brake could make a very high peak load.

Btw, the rear stub of driveshaft in my modren overdrive setup has a twist of about 10 degrees.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Wednesday, February 20, 2008 - 05:05 pm:

Chris,

That's the exact same type of failure I was refering to in my previous posting.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Wednesday, February 20, 2008 - 05:09 pm:

Which brings up the question: why is the inner sleeve keyed to the woodruff key, rather than just floating?

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Wednesday, February 20, 2008 - 07:54 pm:

One thing that kinda bothers me in ALL the analysis is that nobody knows for sure what pedigree the various parts ARE. We know that the hyatt type bearing is original because nobody has ever made repro's of them. We know the solid roller IS repro but both inner and outer sleeves have been reproduced for a number of years by different folks and MOST of them were made well before the Ford drawings were available at the archives which tell us what the metallurgy is and any heat treatment. Chris - I don't argue with your analysis but I am NOT seeking any proof of anything. I run my own taper roller bearing setup but the engineer in me was having a problem with all of the "sweeping" conclusions being made without knowing for sure what really happened. I found it odd that you had 2 identical type failures in a row both of which you blame on the inner sleeve and it sure looks that way. If the sleeve is THAT weak as designed and furnished by Ford, I would think these things would be failing all over the place and everywhere yet many folks run the original setup without incident. I ask the same question I keep asking - what is the pedigree of the parts in question? Are they original Ford or just look like it. One could take a piece of water pipe and turn it down and polish it to fit for an inner sleeve but I doubt it would go very far. Case in point is that the outer axle sleeves of not so long ago were just awful and very soft. Steve Coniff did some proper research and got the metallurgy right and those I am told are very good sleeve indeed. Steve had the original drawings so he knew what he was shooting for. Like I said - I have no dog in this fight but I am most interested like everyone else to learn what is going on but I still think we need to be certain where the parts come from that fail so quickly in as little as 1000 miles?? I guess I also always thought the maximum torque would occur during braking with a heavy car full of people rather than by stabbing the clutch pedal down. On MY T - stabbing the clutch down probably will kill the motor ha ha.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Thursday, February 21, 2008 - 12:01 pm:

John,

Quoting you, "On MY T - stabbing the clutch down probably will kill the motor ha ha."

Maybe you should try a distributor. Also ha ha. Just kidding please forgive me, I couldn't resist.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Friday, February 22, 2008 - 12:18 am:

Jerry:

As for a d@#$%^&*tor I wouldn't know what to do with all that extra horsepower. I stay pretty much stock with 20 HP and none of them are pedigree. My T does run smooth but that is more a credit to Tony Verschoore's motor work and Ford's original ignition design than any handiwork of mine. I had a 'vette when I got married and a Triumph TR6 motorcycle when I was younger and that TR6 would just as soon go for a ride without me. My T is now about the correct speed for me ha ha. I have a new GPS system I take with me now. It isn't so much that I used to get lost as it was that I couldn't remember where I was going in the first place.


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