Forth main bearing or ball cap question

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Model T Ford Forum: Forum 2013: Forth main bearing or ball cap question
Top of pagePrevious messageNext messageBottom of page Link to this message  By mike mclean on Sunday, October 27, 2013 - 11:44 pm:

has anyone tried the ball cap that langs sells are they a good thing rebuilding the engine in my 26 tudor thanks mike


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, October 28, 2013 - 07:11 am:

This one, or the appropriate undersize is the one you want:

http://www.modeltford.com/item/3369STD.aspx


Top of pagePrevious messageNext messageBottom of page Link to this message  By mike mclean on Monday, October 28, 2013 - 09:29 am:

none there undersized small enough to get the clearance I need


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Monday, October 28, 2013 - 09:43 am:

Doesn't Ron's Machine Shop in Shandon Ohio rebabbitt them to whatever size needed to fit your output shaft? His phone number is, or was a few years ago, 513-738-7353. Best to send your driving plate unless you are going to machine the babbitt area yourself.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Monday, October 28, 2013 - 01:11 pm:

Send me your drive plate and ball cap and tell me what clearance you need. Am also able to re-grind the drive plate shaft and face the drive plate if needed. Should be able to turn it around in about a week. $60 for a re-babbitted & bored cap cut to your specs.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Monday, October 28, 2013 - 01:13 pm:

Wow, do they ever have the size listing screwed up.

Fords Tail shaft Diameter is standard at 1.560.

Fords standard ball cap hole is 1.562-50, that is 9/16.

The tail shaft to ball cap clearance is then .002-50.

Universal ball cap, rebabbitted, Standard size. Best quality available on market. (For shaft size from 1.558 - 1.561, Ball cap inside diameter from 1.564.) Requires .004 to .006 clearance for oil."END QUOTE" Langs.



So with .004 to .006 thousandths clearance, you are going to have a lot of oil going down the drive shaft tube as anything after .003 starts the process, an can you imagine giving your rods and mains .004 to .006 thousandths clearance.

Who ever wrote that needs to do some more study!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Lang on Monday, October 28, 2013 - 06:36 pm:

According to the Ford Drawing dated 3-14-1914 Factory number T819D (Part #3369) the babbitt should be machined to 1.666 to 1.667 These drawings are from the T100 Project and can be found at the Benson Ford Research Center.

Here is a thread about it from 2006
http://www.mtfca.com/discus/messages/29/10897.html?1140577270

Steve Lang, Langs Old Car Parts


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Sosnoski on Monday, October 28, 2013 - 07:15 pm:

Steve,

I think you mean the babbitt should be machined to 1.566 - 1.567? That gives a .006 - .008 clearance.

Dave S.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Lang on Monday, October 28, 2013 - 07:42 pm:

Sorry Dave, You are correct. 1.566 to 1.567
Steve Lang, Langs Old Car Parts


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Tuesday, October 29, 2013 - 12:30 am:

The tail shaft is 1.560, you don't fit under .002-50, and sure not over .003.

I don't care where you copied those Spec's from they are wrong!

When it gets that big they are long wore out!

There is no bearings that I have ever done or seen that is over .001 per inch of shaft.

Why would you want a tail shaft jumping up and down in a Babbitt hole 6 to 8 thousandths?

Just isn't done.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Tuesday, October 29, 2013 - 01:07 pm:

Herm,

Those seemingly excessive ball cap to driving plate shaft clearances that you consider "wrong" are actually the way Ford designed it and here is why...

Ford knew that their actual manufacturing tolerances on all the moving parts between the crank shaft flange and ball cap could potentially cause so much runout at the ball cap area; that if a "more correct" clearance was used at this area, then the babbitt bearing could fail very fast. Comparing the ORIGINAL FORD BLUEPRINTS for the ball cap and the blueprints for the driving plate, you will find that FORDS INTENDED CLEARANCE here was .005" to .008".

Surely you have worked on enough "original" T engines to realize how far out of spec some of their machining could be. No doubt, you have had circumstances where you had to face .002" off the back of a crank shaft and/or front of the trans shaft to make it perfectly perpendicular... Brake drums sometimes need .010"-.015" faced off their rear to make that surface flat. And the drive plate occasionally has similar issues. All these issues equal quite a bit of runout at the drive plate shaft and if the runout there is excessive and the ball cap is too tight, the babbitt will fail instead of just leak.

Now, with that said: When I do a fully balanced and blueprinted engine, the final step before bolting on the pan is to get a dial indicator up on the driving plate shaft and see what my runout is as a final check that I have machined & fit all the trans parts properly. Generally I consider somewhere around .002" TIR to be acceptable and it is pretty hard to get much more accurate (in measuring) than that because you can push around on the drive plate shaft with one finger and easily cause the dial indicator to swing nearly .010". There is the clearance in the brake drum shaft bushings that allow some movement and a very slight amount of additional flex that can occur.

I have also had opportunities to work on motors for people that have not been blueprinted, such as when I am only replacing a field coil, worn 3rd main, broken magnets, etc. and I have found T engines that have up to .035 runout at the drive plate shaft. This is the sort of thing that occasionally occured during manufacturing and why Ford wanted a .005" to .008" clearance at the cap. If the clearance was not wide, they could have bigger issues on some engines.

With all that being known to me, here is how I proceed on every ball cap I machine:

If I balanced & blueprinted the engine, I set the cap at .0015" to .002" clearance because I know that everything is properly suited for that clearance.

If it is a motor I have in the shop here that I have not rebuilt and I am doing some "other" work on, I check runout with a dial indicator at the drive plate shaft, and if the runout is right at, or less than the apparent clearance of the brake drum bushings, I set ball cap clearance around .002" to .003". If the runout is more than the clearance of the bushings, then I will take the trans loose from the crank shaft, turn the transmission 180 degrees and bolt it back to the crank shaft, this generally makes the runout either a lot better or a lot worse due to variances in how good the crank shaft flange and transmission shaft were machined. I actually had an engine here a few years ago that had .035" runout at the drive plate shaft and when I took the trans loose from the crankshaft, turned it 180 degreees and bolted it back down, the runout was only .004"!!! This is the kind of thing FORD knew about that prompted them to specify that "gigantic" clearance on ball caps.

If a customer has sent me his ball cap to re-babbit, and he has the technical ability to check runout, and he has verified that he has runout less than the busing clearances, then I will set clearance at that .002" to .003"

If a customer has sent me his ball cap to re-babbit, and he does not have the ability to check runout, then I generally set clearance at .005" to .006"

I also require customers to send me their drive plate when they are having a ball cap re-babbitted for a few reasons:

-First and foremost, their measuring tool or measuring method may not provide the same dimensions as mine.
-The drive plate may be worn tapered and they may not realize it.
-The drive plate journal may have a poor surface finish that would cause rapid wear of the babbitt if not corrected. (I was once sent a fairly pitted drive plate and told by the customer that it is okay because the pits hold extra oil!)
-The drive plate shaft may have been re-riveted and be off center.

Credit: I was initially informed about the large "original" ball cap clearances and adopted the information into my procedures due to an article that I believe Trent Bogges wrote several years ago. I can't find the article right now but I'm pretty sure he was the one that did the research and wrote about it. Maybe someone can post it here if they have it...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Tuesday, October 29, 2013 - 02:19 pm:

By Trent Boggess on Thursday, February 09, 2006 - 12:50 pm:
The two parts involved here are T-743 Transmission Driving Plate Sleeve and T-819=D Universal Ball Cap Front. The related dimensional specifications for these parts says a great deal about what the Ford engineers knew about tail shaft run out, and what the decided to do about it.

The T-743 Transmission driving plate sleeve was actually made from a steel forging rather than bar stock (at least as of 1914). The outside diameter of the sleeve was initially turned to 1.580 to 1.585 inches. After hardening, the sleeve was finish ground to 1.559 to 1.561 inches. Take note of that final dimension, it is very important.

Transmission Ball Cap – Front is actually made up of two steel stampings: the concave ball itself, T-4346, and a steel sleeve, T-4541. In 1914 the engineers specified that this sleeve was to be made from scrap, or fall off, crankcase steel stock. The two pieces were simply brazed together. In later years, I believe, Ford engineers developed stamping techniques that allowed the ball cap to be made from a single piece of steel. Once assembled, and this is a critical point, a short 3/16 inch flat was turned on the outside of the bell at the point were the bell turns into a flange. The flat was turned to give an outside diameter of 4.205 to 4.210 inches. This is the flat that centers the cap in the rear hole made by the junction of the transmission cover and the oil pan. The flat was also used to center the ball cap assembly when the babbitt bearing was being bored to the finish size of 1.566 to 1.567. Few people realize that point, including some of the folks who rebabbitt those caps today.

Now do the math to determine the clearance: if the sleeve’s diameter is 1.559/1.561 and the finished bearing’s diameter is 1.566/1.567, then the clearance between the two is .006 to .008 of an inch.

Fred Houston has for years argued, and rightly so, that there must be near perfect alignment between the crankshaft and the transmission shaft sleeve in order to rebuild a Model T motor that will run with less vibration and with long crankshaft and bearing life. The fact that the Ford engineers set up the clearance between the sleeve and the ball of .006-.008 when they were using much smaller clearances for the other engine and transmission bushings indicates that they knew about the transmission shaft run out. They also recognized that in production the crankcase was built to closely aligned specifications, so they left lots of clearance as well for the fit of the transmission ball cap to the transmission cover/crankcase hole that the ball cap fits into. The dimensions of the hole were set at 4.215 to 4.220 inches, leaving a .005 to .015 inch clearance between the ball cap and the hole it fits into.

Given the design of the Model T crankshaft, the transmission shaft and the transmission driving plate sleeve, it is quite a challenge to get all three of these pieces in perfect alignment. It seems to me that the Ford engineers decided that best they could achieve on a large scale production basis only a .005 inch run out, so they accommodated that by putting some pretty generous clearances between the sleeve and the ball cap bearing, and again between the ball cap assembly, the transmission cover, and the crankcase.

All things considered, it is a wonder that oil doesn’t pour out of the universal joint when the engine is running.

Respectfully submitted,

Trent Boggess


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Tuesday, October 29, 2013 - 05:08 pm:

All of which unless you can do or hire perfect alingment work your better off using the babbitt fourth main as Ford then the non give ball bearring?? Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Sosnoski on Tuesday, October 29, 2013 - 06:12 pm:

Just throwing this out but I was wondering if another reason for the larger gap in the ball cap is due to the movement of the ball cap due to the torque tube. All of the rear axle forces are concentrated on the ball cap. Since the torque tube is at an angle, there is going to be an upward and downward force applied to it whenever you start, stop, hit a bump, etc. A couple of years ago someone measured the deflection at the end of the hogs head and found there was quite a bit of movement. With a tight bearing that is going to be pushing the tail shaft up and down as well which will affect the alignment. A larger gap may help isolate the tail shaft from that movement. So it may not be as much as the tail shaft bouncing around in the babbitt hole as much as the babbitt hole bouncing around the tail shaft?

Dave S.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Tuesday, October 29, 2013 - 08:25 pm:

Tail shafts always dial to Zero, if all the in line machine is done correctly.

I read a piece in some T club where they butcher the area around the crank flange, and crank dowel pins to get room to slide everything around to get a center line for the tail shaft, and all they would have to do is machine parts correctly.

Center line for crankshaft.

Main shaft center.

Flanges cut 90 degrees

One brake drum bushing reamed in alignment.

Tail shaft bushing reamed in alignment with brake drum bushing.

Tail shaft bolted and marked for tail shaft ball cap area to be trued.

If you do that work correctly, Tail shaft will be Zero turn, or you can butcher other parts to try and compensate!

Also you have the Align bore the crank in the center of the block, or what ever way it is off, that is the direction it will be off in the pan ball cap hole.

Not right or left, or up or down but center.

When the ball cap is stabilized with four bolts, while the pan may have a little movement, there is nothing that would effect the ball cap clearance.

.002 will smear babbitt, .006 and .008 will work the crank flange, and run excess oil down the tube.

We have spun poured well over 20,0000 ball caps in the last 47 years, and never have used such ridiculous clearances as stated above, as Don Lang can attest to with cam bearings, rods, and ball caps.

If the rear end pushed into the ball cap area nothing would be effected unless the rear end was being pushed by another car!

You guys are not even reading what you are writing..006-.008 thousandths, Good Grief!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Wednesday, October 30, 2013 - 01:14 pm:

Apparently Herm, these guys are reading what Ford was writing... but those Ford guys didn't know nothin' did they.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Wednesday, October 30, 2013 - 03:05 pm:

Well Jerry, I have poured more Ball caps and machined them then you will ever see, machined to the same spec's as all the thousands of bearings that we have done with out any damage.

If some one machines 6 to 8 thousandths in a ball cap and thinks that it is right, then you can't say much for there bearing machining knowledge.

A ball cap is NO Different then a Rod, or Cam bearing for fitting clearance.

You will start getting movement at .003, and then add .003, and then .008, PLEASE!!!

All you could do is put it in the hole and let the bottom and the sides come up and get what they want.

When hot, the shaft swells just so much. The tail shaft will swell some wear over .001 to about .001-50. So that will give you about .001 thousandths Actual stable oil clearance when hot, and as a rod bearing the shaft will take it out any further that it wants to go.

So if that is what what Ford spec's say, and I don't think so, as it makes no sense to make a drawing of 6 to 8, and cut all the N.O.S. ones that I got out of the ford garages in the 50's, along with the N. O. S Ford 1.560-00 tale shafts, and the ball caps measure out to 1 and 9/16, or 1.562-50.

Ball bearing ball caps we fit at a .000-50 thousandths. So if you get a motor rebuilt, or you call your self a motor builder, and if you have more then a .000-50 run out at the tail shaft, you better be thinking your machining skills over.

Drawings and figures and copies get screwed up all the time, and when you got the blind leading the blind, this is what you end up with, and no one catches it!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Wednesday, October 30, 2013 - 03:42 pm:

Did Henry have time to get everything perfect to your standards Herm or did he sell 15,000,000+??Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Wednesday, October 30, 2013 - 04:39 pm:

Herm,

"...I have poured more Ball caps and machined them then you will ever see..."

You're correct, and Ford poured more ball caps than you will ever see.

As always, I respect your views and skills. I will admit that I think .006/.008 is a bit wide too. The new cap I'm installing gives .003/.004 clearance. Still too loose by your standards but I'm o.k. with it. (The old one was at .010 and there was no noticeable oil leak or excessive oil in the rear end)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Thursday, October 31, 2013 - 12:52 am:

Did Henry have time to get everything perfect to your standards Herm or did he sell 15,000,000+??"END QUOTE"

They didn't use those spec's!!!

The old one was at .010 and there was no noticeable oil leak or excessive oil in the rear end)"END QUOTE"

That's B. S., isn't my first time to town.

Probably wasn't any oil left in the engine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Thursday, October 31, 2013 - 12:23 pm:

If the difference on the prints is .005" to .008", and if their machines were running properly and everyone did their job right that day, then that is the clearance they left the factory with... I have copies of the prints and so do lots of other people. The prints are also on file at the Benson Ford for everyone to look at. There was a reason the clearance was so wide... Yes, if you did all the engine and trans work on a certain engine and properly machined everything, you can use a .0015" to .002" clearance with good results...

The trick here is realizing that the average Model T engine out there is far from being perfect, and that if there is far greater than ideal runout at the fourth main journal, and if the ball cap is one of the only items getting attention on that engine, then a much wider than "ideal" clearance may produce far greater customer satisfaction...

Most of the guys that designed the T were mechanical engineers... Everyone here, with very few exceptions are mechanical philosophers...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Thursday, October 31, 2013 - 01:18 pm:

Herm,

Thank for your well thought out response. As you so aptly suggest, I must be an idiot.

Adam,

Well stated.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Sosnoski on Thursday, October 31, 2013 - 01:30 pm:

I think we are talking apples, oranges and pears here - which goes along with what Adam has been saying.

If someone takes the time and effort to make the tail shaft run out 0.000, then Herm is right that a .002 clearance is all you need.

Most people don't go through all of that effort, or they are simply replacing the cap and not tearing down the whole engine. In that case where there is run out, the .002 clearance is probably not going to work well - hence the wider clearance. Ideally you would want to offer caps in .001 increments - but that becomes a manufacturing and stocking nightmare - hence the choices which are now available.

If you are back in 1920 and are building 6,000 engines a day, you are not taking the time to make the tail shaft run out 0. It is whatever it is when things get bolted together. Contrary to what people believe, Ford knew what they were doing. I would guess that they had done some studies which showed what their process was capable of maintaining for run out, and they chose that spec accordingly. They did not (as Herm has alluded to) have one dimension on the print but machined them to a different dimension. They were machined to what the print said. If the dimension on the print was wrong, it would have been changed.

It would be interesting if someone had the Record of Change to see if that dimension changed over time. The dimension quoted above was from the 1914 print. By that time they had worked out the majority of the bugs and had a pretty reliable car. It would be interesting to see if the original spec was tighter and they opened it up - which would indicate they were having issues with the tighter spec. Did they tighten it up later on which would indicate either their manufacturing process got better, or they determined it really was to much clearance.

Bottom line is that it is a Model T. For most things high precision is not needed. If it slides on easy, spins free and doesn't wiggle - it's good.

Dave S.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Thursday, October 31, 2013 - 01:33 pm:

Your entirely welcome Jerry, Herm.

I am saying where ever the prints came from they are wrong, and the New Old Stock Ball Caps were 1.9/16!

And why would you need to make a pan so straight, and then put in a newly cut wore out ball cap which would have had the same effect?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Trent E Boggess on Thursday, October 31, 2013 - 07:51 pm:

Folks,

The clearance between the front ball cap and the transmission output shaft that I cited 7 years ago are the dimensions found on all of the drawings for the front ball cap and transmission shaft in the collections of The Henry Ford and are dated from 1908 through 1927. In addition to the drawings themselves, the same dimensions appear on the "Record of Changes" that were created and updated as the drawings themselves were up dated. That is to say the documentation matches the prints themselves.

Additionally, I have traveled to Hungary to visit the school where Joseph Galamb studied mechanical drawing and engineering. I have even reviewed his transcripts and know the subjects he excelled in (mechanical drawing) and those he did not (German). Additionally, I had the opportunity to interview Joseph Galamb's daughter, Gloria, before her death last year. All of the information that I have gathered together convinces me that Galamb was a gifted, extremely competent engineer. When I asked Gloria about her father's sense of humor, she told me several of his favorites. The common theme running through these jokes was that they were about people who did stupid things, which is to say, they were doing stupid things because the people in the stories did not use their heads and think about what they were doing.

Joseph Galamb knew what he was doing when he set the clearances of the tail shaft and the front ball cap. There is no evidence to believe otherwise 105 years later.

Having said that, I will say that I do my own Model T engine rebuilds. I have over the years acquired the necessary tools, including a Wilson pan straightening jig, to do the job properly, albeit slowly. I spend enormous amounts of time straightening the pan. I too will machine the brake drum and the tail shaft to get as close to zero runout as I can. If more than .003 wear on the tail shaft is present, I put the brake drum and driving plate assembly together in my Clausing, and grind the tail shaft back to being perfectly round. I can't tell you how many times the transmission goes on and comes off until the dial indicator on the tail shaft shows less than .001 runout. And I pour and bore my own ball caps and machine them to provide a clearance of .002. And I do my final assembly with the engine on it's nose tightening and loosening the pan rail bolts so that the front ball cap slides onto the tail shaft with out binding on the pan or the transmission cover.

It takes an ungodly amount of time to do this, but I do it because it is a labor of love, and because I want my cars to run well. I could never do this commercially and make money at it - so don't even think about asking.

Ford did not have an unlimited amount of time to assemble a Model T motor. They had to make some compromises. Some times that showed up in larger than expected clearances. Other times it showed up by using materials that would squish if the clearances were too tight.

I maintain that a Model T is an intricate set of inter-related compromises. Identifying and understanding these compromises is almost a whole field of Model T research in itself. Many people believe they can build a Model T better than Ford did, but what they may not realize is that their modifications blow through several of those compromises with the result that they sometimes run into trouble later on down the road. The design of a Model T was extremely carefully thought out by some exceedingly bright and competent engineers, using the materials that were available at the time.

Respectfully submitted,

Trent Boggess


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Thursday, October 31, 2013 - 08:14 pm:

And all of the above is why I created my "floating" main transmission shaft. I can take any decent ( i do basic checks to ensure they are not junk) parts and simply assemble. This way the transmission essentially runs between centers and no strain is created between it and the crankshaft. It is a simple fool proof solution


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Thursday, October 31, 2013 - 09:21 pm:

Thank you Trent!! Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Walt Berdan, Bellevue, WA on Thursday, October 31, 2013 - 09:24 pm:

Les,

And I'm using one of your modified shafts in my '26 coupe and like it. Good stuff in my book.

Walt


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