Rear end rework for naught

[wings515]

Well I'm back again with another tale of money misspent.  I reworked a 41 rear end by installing new axle bearings, seals and brake wheel cylinders.  Also installed an SKF Speedy Sleeve on the pinion shaft along with a new seal. Cleaned the whole axle and painted ready to install on my PT81 truck.  Dropped the truck rear end and when I compared the two, the spring perches were on the opposite side of the axle shaft.  What a bummer! 

 

Now I have a perfectly good rear end that I can not use. If anyone wants this they can have it for the cost of the parts I installed at $200.00.  If they are close to North East PA, I will be willing to meet them half way to deliver the rear end.

The main reason I wanted to change the rear is because the one in the truck is leaking at the pinion.  Since I did the rework on the 41 and found the Speedy Sleeve, I have ordered another sleeve and seal and will be re-installing my old rear in the truck.

 

If anyone is interested, I also have a 41 steering box and column that I will throw in.  I got all kinds of stuff about 10 years ago from a 41 and thought it might have some use for my truck.  I did rework the engine and that's in the truck now.

 

My misfortune is your gain.

 

 

[Plymouthy Adams]

flip the perches...no big deal...

[Young Ed]

You could also swap the diff into the truck housing and save some of that work.

[greg g]

Tractor supply sells spring perches in their trailer parts section.  Many folks have used them when swapping rear ends.  Inexpensive and nearly perfect width.

[wings515]

I initially thought about cutting off the perches and mounting them on the other side but that sounded like a lot of work and I don't think my welder can do the thickness.  I will look into the spring perches  at Tractor Supply.  If it looks good I might go that way.

The portion that I rebuilt is not in the differential but at the brake ends. So doing the rework again seems like a lot of work. I also looked into the adjustment of the differential gears to the pinion and it appears like it is much more than I can handle. The manual shows a holding fixture required to make all the adjustments.  I just don't feel comfortable tackling what looks like a big job. 

 

Any thoughts on what it takes to remove and adjust the differential?

[Young Ed]

 

Any thoughts on what it takes to remove and adjust the differential?

 

If you swap the assembly from one axle housing to another there is no need to adjust it. Once you pull the axles its just a bunch of nuts and a gasket to redo. You might get a slightly better ratio out of the deal too.

[wings515]

Another reason I thought I needed to change the rear was what I thought a lot of rotational slop on the pinion. I guess the pinion moves about .030" to .050" radially.  Is this OK?

As an alternative, does anyone know of a differential service shop near north east PA.  I've done some searching on the net and the closest shop is in VA.  I'd be open to shipping it off to get it professionally rebuilt but sending it to VA will be very costly.  It looks like I could just send the differential and pinion since the axle bearings are replaced. 

 

Thanks for all the replies.

[Oldguy48]

You might try Snyder's Machine Shop in Northumberland, PA. I had them rework a 8 3/4" Mopar rear that I installed in my P15. The owner is a Mopar man, and does excellent work.

Wayne

[wings515]

Wayne,

Thanks for the tip.  I am going to look him up right now.  On a MUCH better note.  During my time of contemplation just before falling asleep, I pictured the rear in my minds eye.  Dummy that I am, it is the correct rear end, I just had it flipped over.  To confirm my idea, I went to the Hollander manual and this rear was used in every MOPAR product from the late 30's into the mid 45's. The only difference was the gear ratio.

 

So after contacting Snyder's, I may just install the 41 and call it quits.

 

Thanks again to all for the suggestions and help.

 

Dan 

[Don G 1947]

Dan,

 

Unless the rear end is making noise or you have a specific reason, you don't want to adjust the ring and pinion that have been running together for a long time.  If you attempt to adjust them you will likely create lots of noise in the rear end.  Unless there is a reason, it is best to leave well enough alone when it comes to a functioning ring and pinion set.

 

Do you have a part number for the speedy sleeve?

 

Also, to be sure you have the axle right side up check for the vent.  It goes on top.

 

Don

[wings515]

Well I again went through a comparison of the two rears.  With the wheel cylinders on top, the brake lines attached using the clip attachment points, vent hole at the brake line junction block at the correct location and the pinion shaft below center line, I checked the rotation of the pinion vs. the wheel rotation on both rears.  It all was the same except the spring perches were reversed.  The truck had the perch on the bottom of the axle and the 41 had the perch on top.  Now what really gets me, the Hollander Interchange Manual shows the same rear from early 30's too late 40's.  I have no idea how this rear is so different. The only possible thing could be that the 41 is from a 7 passenger vehicle.  Hollander has exceptions for this model but does not give an indication what the difference are

.

I did speak to Mr. Snyder and he agreed that the slop I have seen may not be the pinion but it could be the spider gear.  Also if I do have the rear adjusted using the gears that are in it, there could be a lot of noise generated.  If an inspection show some gears have to be replaced, the availability could be an issue. Since I do not drive this truck on a daily basis, both Mr. Snyder and I agree to leave well enough alone and just correct the pinion leak.

 

So at this point I have ordered another pinion seal and Speedy Sleeve.   The pinion has a significant depression on the shaft surface.  The Speedy Sleeve should correct this and provide a good sealing surface on the pinion. I'll install both, clean and paint the 39 and re-install it.

Since I installed new wheel bearings and wheel cylinders on the 41, if the Tractor Supply perches work out, during the winter, I'll weld them on and remove the others and now have a spare rear.

Thanks for all the suggestions,

Regards,

Dan

[wings515]

After talking with my wife, the one with the common sense, her suggestion was to look at part numbers. I did find a part number on the differential housing casting for what I thought was the 1941.  It is 663473.  Checking the parts book for the PT81 the number for this part is 663472.  A quick search on the net only listed one instance where it stated this rear was for a 1946 Dodge WC.  No wonder it does not fit!  The Hollander lists years 37-42 for 663472. Also a small note- 39-11 and 41-11 ratios use different cases.

So so much for the mystery.  This is not a 41 rear.

 

If anyone is looking for a rear for a later model MOPAR, I've got one.

 

Just waiting for the Speedy Sleeve to arrive.

 

Regards,

Dan

[greg g]

Your observations seems contrary to what is the usual case.  Trucks wanting to ride higher than cars seem to have their rear axles mounter below the leaf springs, and cars usually have their axles above the springs. Cars designed to ride lower usualyl mount the axle above the springs.  Not saying you are incorrect but it seems opposite conventional wisdom.

[Young Ed]

Also I would be quite surprised to find out a 46 WC rear end is different at all from a 39 plymouth pt81 rear. The plymouth trucks are the same as dodges underneath. This is the rear in my 46WC.

 

[wings515]

Yes, my PT 81 looks just like that.  But the "other" rear has the perches on the bottom.  Also noticed the perches are further apart on the "other" rear by about 3/4".   Maybe this rear is from a later than 46 car.  I can totally agree that trucks would probably ride higher than cars.

 

In any case, the 39 rear has been wire bushed, production weld splatter ground and overall cleaned and painted.   Ready for the seal and Speedy Sleeve. 

 

After seeing your setup, I am going to take a picture and post the "other"

 

Young Ed, I see you have pulled the axles and differential.  Can you explain why this was done?

 

 

Regards,

Dan.

[Young Ed]

Yes, my PT 81 looks just like that.  But the "other" rear has the perches on the bottom.  Also noticed the perches are further apart on the "other" rear by about 3/4".   Maybe this rear is from a later than 46 car.  I can totally agree that trucks would probably ride higher than cars.

 

In any case, the 39 rear has been wire bushed, production weld splatter ground and overall cleaned and painted.   Ready for the seal and Speedy Sleeve. 

 

After seeing your setup, I am going to take a picture and post the "other"

 

Young Ed, I see you have pulled the axles and differential.  Can you explain why this was done?

 

 

Regards,

Dan.

 

New wheel bearings and swapped in a 3.9 car diff unit. My stock one was SHOT! It had about a half inch of freeplay and the teeth were almost sharp I think from someone assembling the rear with no shims.

[wings515]

Well if you need the internal parts, the "other" rear is for sale.  It has new wheel bearings and speedy sleeve installed on the pinion.

 

Just a thought.

 

Dan

[Young Ed]

Any reason you arent swapping that diff into your truck housing?

[wings515]

After talking with Mr. Snyder (look about 4 post before) what little slop I have in the rear could be attributed to either the Pinion or the Spider gears.  He determined from my description, that an adjustment to the rear would probably make it very noisy and if the rear does not leak, leave it alone.

Once I put in the new seal and speedy sleeve, the 39 rear will be acceptable.  The only reason I started this rework on the 4X rear was because I had it and could do the rework while still driving the 39.  The goal was to put a rear in the truck that would not leak.  Well after putting in the sleeve and seal on the 4X I  found this would solve the initial leak in the 39.  Other than the leak, the 39 ran fine.

 

I just had this idea that I could rework the 4X and have a "new" rear and do a quick swap.

 

BTW, I also installed two new brake wheel cylinders.

Dan

[wings515]

I tried to send a picture of the 4X rear but the file size is limited to 1MB. Right now I don't know how to decrease the picture size from 2.2 MB to under 1MB.  I used the picture compress function but it did not reduce it enough.

 

Maybe later I can figure out how to reduce the size.

 

[greg g]

set your camera to a lower resolution.  You rally don't need High Def pictures for the forum.

[wings515]

This is the final post of this adventure.  I purchased another Speedy Sleeve and seal and installed them into the 39 rear.  After installation of the brake lines, mounting on the truck and connection of the drive shaft I again did a test of the rotational slop on the rear.  Since it's been months since I started this I had forgotten how much slop there was on the rear.  About 45 degrees.  Taking the suggestion from a previous post, I went to Tractor Supply and purchased two different spring perch kits.  A 3500 pound and 5500 pound.  Don't know why but the 5500 was less expensive than the 3500.  In any case I bit the bullet and installed the new perches on the 41 rear.  Measure twice, weld once and my little MIG welder did a great job.  Now came the hard part, grinding and chiseling the old perches of the rear.  About 4 hours later all the material from the old perches were gone and the rear was painted.  The next day the brake lines were switched from the 39 to the 41 and the rear was installed.  It fit perfectly!!!  Connected the drive shaft and had about 10 degrees of rotational slop.  Bled the brakes, re-installed the gas tank ( removed to get the sender unit fixed) and took it for a test drive. All good and no oil on the floor.  Drove it out of the shop area and into the garage for safe keeping until the spring.

I feel real good about the outcome.

 

Regards,

Dan K.

[Niel Hoback]

Congratulations on a job well done.   Let's see now, whats next? Oh yeah, Go enjoy!!

[Don Jordan]

I hate to sound like an idiot but what is a Speedy Sleeve? I changed the seal in my diff. and it still leaks. Perhaps this could solve my problems. (some of them anyway)

[Merle Coggins]

It is a very thin metal sleeve that is installed onto the shaft or flange where the seal rides, giving it a new, smooth, surface for the seal to work against. They are available in many sizes. Measure the diameter of the sealing surface of the drive flange, with a caliper or micrometer, and ask the guy at your favorite parts store for a Speedy Sleeve that size.