Five years ago I took out my rearend because I was having my engine worked on... Life happen... I got distracted... But every summer I would say this is the summer I will work on it.
Yesterday a friend invited me to his 92th birthday party on June 30th. He is one year older then the car. Now I have a goal!
I looked up information and found a old post with a checklist. I though that is handy (and then realized that I made it;). See: http://www.mtfca.com/discus/messages/257047/329642.html?1356545874
Anyway I plan to post progress here on the forum. I just realized that I may visit my brother for a week between now and then, so I will have to buy parts before the!
Call Dave at Chaffin's Garage in So Calif.
He is the West coast T supplier and has all differential and Ruckstell axle parts!
Thanks Steve! Over the last few years I gathered new and used parts including the the modern driveshaft bearing from Chaffin's.
Today I gathered parts from the four winds:
Note the checklist on the clipboard.
Now I need to sort the best from the good and bad.
Here is my first question.
For a 1926 car will both of these work? Is one more correct than the other?
The one on the left was originally on the car. The one on the right has a better axle and the bushing inside has little wear.
Hi, welcome to the journey. Here is a complete discussion of a recent rear-end rebuild:
The two torque tubes, either should work fine as long as condition is good and straight. I can't see the bolt-to-the-differential end, so a limited view. The one with the smooth, gradual, taper, should be good for any T from 1920, until the end of production. I am guessing on that, because I can't see the other end of it. There is a small change where and how it mounts onto the differential. The change from "enclosed" to "open" bolt pinion spools was made about '19/'20. Early and late versions of the spools, housings, and torque tubes all have minor changes in how they fit together. They can be intermixed, however, they don't quite fit right, and there may be spacing issues with the pinion bearing. Some cutting and grinding may be required to fit mis-matched pieces.
The exact size, and taper varied somewhat. Earlier ones have a lighter look to them, and a more elaborate six bolt flange to attach to the pinion spool and differential housing. The earlier one also has a "ridge" around that six bolt flange, while the later ones are flat and smooth.
To my eye? Your tapered torque tube looks like it probably is the later one ('20 to'27). But you will need to check the back end to be sure.
The other one, is still a bit of a mystery. The "stepped taper" clearly was used by Ford in original production. However, it seems to have been considered a minor variation, as no clear records indicate the reason, or exact time, of the use of the stepped torque tubes.There is considerable evidence that they may have been used as early as 1922. However, the majority of them found on intact cars indicate that they were mostly used in '26/'27, and many people consider them to be '26/'27 torque tubes. The fit is interchangeable with all the common post '20 tapered torque tubes. So, use whichever one tickles your fancy (as long as the gradual taper one doesn't turn out to be an earlier type?), or maybe whichever one is in the best condition.
That is my opinion and understanding.
We have the stepped type on our late '26 coupe and cleaned it out two months ago by welding a drill's small wire brush to a long rod.
Ignacio, Thanks for the link! I look through it quickly. I can tell I need to look more.
Vieux, Yes mine came from a 26 closed car as well. I assume it is original.
Wayne, Thanks for all of your wisdom! I will try to get a photo up of the other end tomorrow. It looks like I will us the smooth/gradual one because it has much less wear on the bushing. I found that the drive shaft in that tube has a bad key way making it not serviceable. I will get back at it by making it a blacksmith project.
Thanks again for all your help!!!
I spent a few hours reading the mtfca manual. All the details!
I mounted Chaffin's bearing it all looks good, but the screw on the collar rubs against the inside of the tube.
Is this tube compatible with a open spool bearing? Or do i meed to grind out some space in the tube?
The instructions mention that this may be a issue.
Grind the inside of the tube as necessary for the set screw to clear.
Some folks (me included) have ground on the head of the set screw after the final tightening with loctite, but John Regan frowns on that practice.
I have been filing away for a good part of the evening. I have just about got it, but filing the bolt head seems like a nice idea;)
If you do decide to grind on the head of the set screw, be sure to do it after the loctite has set up after the final tightening and grind as little as possible.
Also, the bushing at the front of the driveshaft should be properly reamed and faced per the OEM Ford procedure in order to maintain the proper pinion depth just in case the collar and set screw ever get loose.
A small die grinder is good for removing those bumps from inside the tube. It comes in handy on lots of jobs, and isn't terribly expensive.
Thanks Mark, I have ordering a the drive shaft bushing on my list.
Steve, I decided to stop using the file and find someone with a die grinder. That is a good idea. I can wait to do that since I have some other things to check before I put parts.
Thursday the rebuild came to a stand still when I realized that the right housing is not usable. The surface where the steel thrust washer goes was missing a pin. The washer spun and the surface was dished out about a 16th inch. I was able to get a rear axle from a friend. The housings look good.
Now another question. I placed the axle in the housing as the rebuild book discussed, the axle seems to be off center 1/16 of a inch. Is this acceptable?
The method that I used to figure out if the housing is straight was to hang the housing upside down. I then laid on the ground and found a socket that is just under the size of the narrow gap. It had about 1/32nd space. On the other side it had just over 1/8 inch gap. I am trying to figure if than means I should try the heat and quench method to straighten it.
Do you get the same result on both sides?
If it's a common style axle, like 1918-25 or 26/27 i wouldn't bother straightening it - a better replacement half is easy & cheap to find in USA. But don't throw it away - some day the rejects of today may come in handy
Thanks for your response. This is for the 1926. Yes you are correct that these are common. If needed I can loose for a replacement.
My question is when is a axle considered bent. How is it measured? What is acceptable? 1/4"? 1/16"? 1/32"? 1/64"?
I don't see this mentioned here on the forum or in the mtfca repair book.
I don't know the tolerances either Matthew.
Crummy part is; if there is a bent housing, we put undo stress on the diff housing, gears, axles, bearings and sleeves and then potentially risk breaking an axle or something else from the constant flexing. If I have my head on square.
Thanks Duey, I believe you outlined the issue correctly.
Today I was able to locate a flat surface to check the alignment. My neighbor had a piece of marble he gave me. (None of my work benches was even near flat. On top of that I used two squares to make my orthogonal projector rearend tester. Squares are from the Model T era.
I measured the housing to be within about 1/32th of a inch. I will move forward with rebuilding.
I am thinking that I may do a step-by-step description of my rearend rebuild.
First I removed the rearend like Steve did here:https://www.youtube.com/watch?v=8mZzAt9Q_4k
Except I used a engine hoist to hold up frame/body of car.
I disassembled everything five years ago, but recently acquired a rearend for parts.
To remove u-joint I drilled a hole in the u-joint pin and pushed it out with the punch. Of course I did this when it was installed through inspection hole in driveshaft to.
Today, I went through the parts. Here is what I found.
The u-joint was re-riveted.
The surface on the end looks nice.
I measured the play with a copper wire.
The wire was a bit larger than the maximum recommended .020". And it didn't fit in the gaps.
The pin hole had no signs of wear.
This is best u-joint that I have, so I plan to use it!
It should work fine. Before you install it onto your drive shaft permanently, check that it slips easily into the back of the transmission and onto the front end of your driveshaft. Being an original U-joint it should fit fine.
Some of the reproduction U-joints require some grinding on the corners and flats to fit properly into the transmission.
I also think it should work. Just remember you can't overfill with grease there - they wants lots of it, thus the large cup.
I think it's interesting Ford gave instructions how to tighten up a worn u-joint in the first Model T handbook for owners from 1908:
I purchased two grind stones to widen the torque tube for the improved driveshaft bearing screw and wore both grind stones down to their steel shafts. There was hardly any difference in clearance and I saw to it that the screw took the blunt of the modifying. It works now.
Thanks for telling me to check fit in engine. It would be a lot easier now to fix.
Very informative! I wonder how often people go to all that trouble today to refresh a u-joint!
Wow! You have quite a restoration project. Here I California we are so spoiled with good parts. I didn't realize that tube needs to be widened for improved drive shaft bearings. Thanks for sharing.
On the journey,
Okay now that the U-joint is off out comes the axle. To remove the pinion gear Steve shows a handy method in his video here:
But for me the nut was loose! No need for tools, the gear also came off by hand. Here are the parts after disassembly:
The axle looks perfect on the U-joint end. I measured 1.000 inch.
But on the pinion end the keyway is badly worn. And there is a bad groove on the shaft. Obviously a loose nut is not a good thing on a drive shaft. This is a great example of a bad drive shaft.
The thrust bearings races are cracked and chipped. This is what caused the grove in the drive shaft.
The inner bearing sleeve was easy to pull off by hand. Again because of the loose nut there is wear from the keyway pin.
And the sleeve is cracked on the other end.
More great examples of unusable parts.
The cage on the pinion bearing is loose and flexes. The bearings should measure 0.562 inches, but I didn't go to the trouble measuring.
Another example of parts to set to the side. Good thing that I plan to use a modern pinion bearings!
The drive shaft spool looks almost perfect until detailed inspection. There is a bad wear mark on one side. No point in checking if it is desired 2.375 inches. This will be core for a modern pinion bearing;)
The drive shaft bushing was removed using a spark plug socket. This was just large enough to push the bushing but small enough to get past the rivets in the drive shaft.
The bushing is babbitt, so it should be replaced, but the dimensions look nice.
Note the Ford logo (where hole was drilled). Every part seems to have it!
Actually, the upper bushing is made out of good babbitt (or some kind of core that's covered with good babbitt) so if it isn't worn out, there's no need to change it. But when it's out, it might be damaged & then it's time for a new bronze bushing..
Finally the pinion gear was inspected and it needs replaced.
Leaving me with the following usable parts:
I wanted the correct drive shaft and it is good to have a usable drive shaft.
Thanks Roger! I will hold onto using the original bushing.
I see a new Fun Projects driveshaft and pinion bearing kit in your future...
I've found the best way to rebuild a rearend is jogging and squats. ;) Sorry, couldn't help it!
Looking forward to more! I saved about as much also.
Grease cups and radius rods are all I was able to save and one radius rod is SHOT. The cotter key holds it together but don't tell anyone or I'll be in trouble.
Save it but get a new bronze bushing for the driveshaft tube and use it if you would. :-)
Mark, yes I am using the modern drive shaft bearing. I got it from Chaffin's. His does not need shims. I still need to get the U-joint pin, so the drive shaft is on hold until then. I did barrow a die grinder and it took some time to grind down the inside of the tube.
Matthew, yes I do need to get out jogging to get my rear end in shape! It is just so hot and if I do that I will not have time to work on my rear axle;)
Duey, The parts that you started with are in much worse shape. I hope that you get in contact with some model T folks. You may need to go out of state, but model T parts are not That hard to get. From your webpage I would think that you are restoring a very rare car. At the Bakersfield swap meet some people were almost giving away parts. i hope the best for your project.
Okay time to get the checklist out to start going trough the rear axle parts. (The drive shaft was just a confidence builder.)
The pdf file:
Rebuilding_Model_T_Rearend-330311.pdf (55.8 k)
I made a jig to hold the housings. Simple just a piece of plywood with to C clamps:
The blue lid is what I traced for the circle. Then it should be easy cutting with a jig saw. But I need to get a blade, so I used a chisel and hammer...
Here is the original axle housing:
Can you see any problems? Perhaps a close up helps.
Hint there is more of a issue then just the pins worn off. I saw that, but it was only recently that I noticed this:
The fact that the steel washers were not flat cued me in.
Egads, you can barely see where the locating pins are (what's left of them) Yes, you could machine that flat, but then you'd need thicker thrust washers. Off to the junk piles, gotta be better parts out there somewhere!
I also made my own sleeve removal tool. No, it is not that I was too cheap to spend $10 for one. The issue is that I destroyed one on stubborn sleeve.
Here it is in pieces:
The tube is from an Olympic weight set. Even though it I thin, the steel is very strong. The other parts are: short wood dowel, old saw blade, socket that had to be cut to fit bolt through it.
Here it is in action.
Note I put a line on it to make it easier to locate hole easier.
I had to get a different housing from a friend. I traded him a compete rearend for Model A parts. A good deal for both of us!
I also made this axle wrestling tool when I had stubborn sleeves.
I like this better than risk bending the housing in a vise.
After removing the sleeves the ID was measured. Ideally it would be 2.210 inches all the around. But if not shims can be used.
This mic is not the best for measuring the inside. I should get calipers.
I also cleaned/checked the 13/32-16 threaded holes. Sometimes someone forced in a more normal sized bolt.
My bolts are a mix of studs and original bolts. The dross are fine, but I need at least four more studs and castle nuts.
Next the gasket surfaces were cleaned and burrs were removed.
Then bushings for the springs need to be replaced.
The bushing on the brake cam also needs to be inspected.
The brakes on the replacement housings are different. Note the round washer on top missing as well as the recited tabs are just punched tabs.
Which one is a newer design? Do I need need the round washers?
I believe the backing plate with the brake shoe tabs punched in are the later ones.lf you are fussy,you might as well find the washer/cover.
I am convinced rear ends came from the factory with mismatched housings.l have torn apart way too many 26-7 rear ends with both for it to have been where a housing had to be replaced.
Thanks Jim. I will likely use a matching set, but was noticing the difference. I was wondering with the punched tabs the washer was included on the cam.
Is the washer on the brake can important?
I noticed that after l posted.God's, honest truth is,I've never seen that before.Can't believe that was missing on all the late housings I've had,but like engine pans and various other things,these could have been discarded because they were in the way.
Also,maybe that is some accessory to stop the band from twisting.
The tabs are important to hold the brake shoe in place - not the washer on the cam. Guess that's why they changed to the style without washer but with simplified tabs made from the backing plate material.
If it is correct that the washer on the hub was discontinued, then I am sure it has been discussed here on on the forum before.
I just took a look at all the major suppliers and none seem to carry the round washer on the nut. I think it must be safe to assume it is not so important. I will move on with the rebuild.
Before moving on I will double check my housings. Some reason the MTFCA rebuild book has checking housing during assembly, but I think it would be better as one of the first steps.
Bump to get rid of the spam
I am not sure, but I think this may be a leather seal. There was also a rubber ring. That must have been to seal around the sleeve. It looks like the seal wore from the outside rather than around the axle.
The axles look nice on the gear side.
But on the wheel side the keyway is not so nice.
And they are worn down to 1.044 inch.
I have some other axles that are okay, but it would have been nice if this was a good set.
The gears are in excellent shape so I will save the axles to use the gears.
The roller bearings look good, except for the one with a really loose cage. Another one had a cage with some play, but I was axle to peen that one to tighten it up.
On detailed inspection all are worn more than the one or two thousands required.
Is it true that 0.497 inches or less is too worn? That is what the manual states.
I noticed that they seem to have hardened plating on the surface. When I was cleaning the grease off I saw metallic-like glitter. I imagine most of the bearings that I have are worn past this surface plating.
I really want to get some advice on the bearings because mine are about 0.490-0495 inches. I need to figure out if I should use them.
I would replace them. After all the work that goes into rebuilding a differential why not get good real Hyatt bearings? Real Hyatt bearings can be had from old rear-ends. Mine were chewed up. I was able to salvage 2 good ones and a good axle side from half of a 1927 differential that club member Clint Alred had sitting open in a forest for years and was green with algae. The ring gear and casings were loaded with sand but the Hyatt bearings inside were pristine.
If the rollers are pitted in the surface or if they have worn conical, then I would try to find others. Put the best ones inside and the more worn Hyatts can be used in the outside positions. Sometimes the tolerances in the housings and the thickness of the new outer races stacks up, so only worn Hyatts can be fitted. Thus I wouldn't trash 0.495" rollers out of hand - it depends.
The insidious thing about Model T roller bearings is that the tolerances created by worn rollers is actually twice as large as the wear measured on any given roller. The axle can be thought of as being suspended between two rollers. If there is .004-.005 wear on the roller on one side of axle, then there will be an equal amount of wear on the roller on the opposite side of the axle. Ford machined roller bearings, axles and sleeves in order to provide total clearances of .002-.003". Using well-worn roller bearings (.495) will result in a total clearance of .010" or more. This essentially allows the axle to flop around in the axle housings.
A similar effect occurs when re-using drive shaft roller bearing parts that are well worn, allowing the driveshaft Pinion gear to flop around in relation to the differential ring gear, making it all but impossible to set up the ring and pinion gears with .005-.010" clearance.
Next, if you are going to use previously used axle shafts in your rebuild, try to find ones with the name Ford in script stamped into the outer keyway. This indicates the axle is made out of EE steel instead of AAA or AAX steel. The later are vanadium steels that tends to crystallize and break, especially at the rear hub. EE steel is a carbon steel specially heat treated that is less prone to breakage because of slight but continuous flexing of the rear axle shaft within the housing.
Also check that your driveshaft is straight. Surprisingly a great many original driveshafts are bent. Using a bent driveshaft in a fresh rebuild will result in vibration, noise, and rapid wear of hard to find parts.
To confuse things a bit, my '27 (March production date) does not have the "stepped taper" driveshaft housing. There is nothing that stands out to me to make me think that it's not original.
It doesn't seem like any authority has stepped forward say if and when the tapered drive shaft housing ended. So I guess that you can get past the judges in the next show
I agree that the inside of the axles seem to have nice bearings. I have actually gone through a lot of bearings and none seem to meet the requirement of .498-500. What was the measurement on your bearings?
Here is a bit more of my story of looking for bearings. The original four had loose cages. I got a T axle used in a homemade trailer. A friend gave me a box to look though. I bought four in Bakersfield they were tight and filled with grease, but when I got them home and cleaned them there was rust under the grease! And finally I got a old rusty axle, two bearings were good, but undersized.
Roger, thanks for the advice. There is hope that the housings and sleeve are tight. Also, I will double check that bearings are or conical.
Trent, thanks for all your input. Your insight that the axle play doubles from the bearings on each side is important!
Is it okay to shim the sleeves to make up for bearing play?
Trent your advise regarding the EE drive shafts is insightful. The shafts from the last rearend that I took apart apparently are EE.
Unfortunately they are not serviceable.
The ones I was considering have Ford marked on the inside near the inside bearing surface.
The outside sleeves looked like this:
The insides were up to the desired tolerance of 0.070":
I also learned how to identify the left and right. Make the arrow point down the why ever aid the hole is on that tells you if it goes on the left or right. I actually took the photo in reverse here.
Unfortunately my Hyatts are installed now so I can't tell you what they measured. I went by the book values which I cannot quote because I am on vacation :-) Put good ones on the inside for now. As you know, the outer bearings are much easier than the inners to replace and you can move forward on your diff rebuild.
Thanks Ignacio, I will follow your advice there.
Now for the differential and spider gears.
The book says the gears should be loose fit (0.005-0.007"). With the gear ID 0.752-0.0753". Here is what I got:
The bearing diameter of the spider arm should be 0.746-0.747:
Some reason both measurements were on the low side, but it seems reasonable.
The mounting stub on the spider should be 0.622 and tight in the housing.
All is good on the measurements, but I found this on the gear.
So would this set be considered usable?
I'd be concerned about it. I'd find another. Actually, it looks like there's another one there with a similar problem.
I found a chipped tooth on one of mine. I have a call in to one of the vendors to see if they have a single to replace the one with a chipped tooth. The spiders don't turn except when going around a corner, so the chipped tooth MAY not be a big problem, but I want to replace it anyway. That chip in the edge of your bore COULD lead to the gear splitting. While they don't turn going straight, they do indeed transmit your drive torque and more importantly, your BRAKING torque.
Yep replace those spider gears. Not worth having 2 torn up ones in there.
Thanks guys! I had two sets with similar problems. I was wondering if they were possibly made this way. I may mix and match or just use another set.
Hal, yes the MTFCA rebuild book gives the same ominous warning that breaking forces are transmitted through the spider. Best to be on the safe side.
Now for the fun babbitt trust washers! Here is what I found!
One with Ford script.
The other with FORD in caps.
The one with Ford script had very little wear. Evidently it would have originally been 0.205-0.210" thick.
You can see the difference in wear on the back.
Obviously, I will be replacing these with bronze. But the three rearends that I took apart all had the babbitt intact despite other issues. I will save the babbitt for future projects perhaps pillow block bearing on some old machine;)
The steel trust washers may look okay.
But they are worn down bellow the 0.090" specifications.
Here is washer that shows what happen when things get too worn.
Now time to look at the left differential housing. Here is one I can't use:
The shoulder is halfway gone!
This one on the other hand has a good ID. It should be 1.812" giving about 0.005" clearance between axle bearings.
But notice there is more that recommended wear on the outside shoulder where the bronze thrust washer will set.
The inside looks good too.
Is this really how it should be wired?
I just finished a rebuild on my 25 rear axle and that is also how the ring gear was wired when I pulled the rear end apart. I rewired in pairs but used the materials and techniques listed in this forum on how to properly safety wire.
Now for the right differential housing.
The one in the left had too much wear inside the housing.
So I plan to use this one:
But it has a bad trust bearing pin.
So I removed it by drilling, tapping, inserting bolt with nut plus washers, and finally twisting nut for removal. (Actually redrilling and tapping a bit more was needed. Spot came out the final bit on the tap.)
As you can see I need a class on centering.
I inserted new pin with drill chips on bottom so that it would not go too far in.
Then I used a center punch to lock it in.
Thanks for the pointer. I found this info on safety wiring the ring gear bolts:
Is there a favorite tread on the subject?
That's the one. That thread was the most helpful to me.
I was in the area, so I stopped by Chaffin's Garage in So Calif.
Glen and Dave were very helpful. Glen took me on a short tour as I got some used parts.
It was very reassuring to read the sign behind Glen;)
Now, I will start the assembly;)
For those who have never visited Chaffin's, Steve posted some photos here:
I installed a new drive shaft bushing using a large socket and shaft.
Then I drilled out the oil hole.
I still need to learn how to properly peen the u-joint river pin. But I believe the drive shaft can be set aside for now.
Here is my first try at safety wiring the ring gear.
Today I went to Harbor Freight to get a dial indicator to check the backlash.
I used a scrap piece of marble counter top and 220 grit sand paper to sand down the bronze trust washers. Back and forth ten times, turn 90 degrees, sand back and forth 10 more times, turn the same direction 90 degrees, etc.
One issue I saw was that the cotter pin almost touched the differential housing. I guess I will need to cut it off.
Thanks Mark! I feel like I am going down the home stretch.
This morning I peened the u-joint pin. I wasn't sure how to do it so I stacked a bunch of 2x12 to hold up one side.
Then I put a punch in a vise and hammered with another punch from the top.
Looks like you'll make your deadline.
Steve, thanks for the encouragement! I guess I am 11 1/2 years away from my friends 93 Birthday- next June 30th.
I had to assembly both housings multiple times with four bolts until I got the thrust washers sanded down where I could finally just turn the driveshaft by hand.
Then I was ready to do the final assembly of the driveshaft. I used Permatex high tack gasket sealant to seal the driveshaft that didn't need the gasket/shim. I also put the sealant on one side of the housing to help hold the paper gasket.
With the gasket in place the driveshaft turned freely by hand.
How'd your gasket fit between the housings?
Mine didn't fit at all but they're ten years older than your housings.
Another axle that'll be ready to give good safe service! :-)
I had to trim a bit off of the gasket, but on the rush I didn't get a picture. I did get the gasket wet to make it easier. My housings are 1926/7. What are yours?
Hehe, a mixed bag.
15? LH (no ribs out on the outer flange) & 16+? RH (ribbed flange).
The only issue I had was about 1/8" needed to be removed that hung over toward the driveshaft housing.
After five years of waiting my car will be complete again!
I know that there are fancy stands that some people use, but the engine hoist worked for my touring.
I used a 2x4" block on the drive shaft tube to attach the shackles to the perches.
Thanks MTFCA for all your help and insight!
Congratulations, that is quite an accomplishment. You've joined the brotherhood of differential teardown and rebuild. I like your method of lifing the rear. Is the hoist attached to the frame? Some kind of strap used?