Pinion Seal Replacement

[Jim Sullivan]

This one is for all of you differential experts as this is the one thing I have yet to overhaul / rebuild. The pinion seal on my posi rear in my four door started to leak after my first outing of the spring. So, I got it up on stands, pulled the wheels and drums, removed the drive shaft and checked the preload before I took the flange off. The preload seemed low at 5 inch pounds. I didn't look up the spec, but I figured I would replace the seal and torque the flange nut until I had the same preload or just a couple inch pounds more. Well, first I tried to seat the seal flange against the housing, which apparently it's not supposed to do, and the seal didn't seem to have a nice press fit. I had to put it back together to move the car. When I installed the flange, I tightened the nut a little more than snug. Then checked preload, same 5 inch pounds. It got to where I tightened the nut as tight as I possibly could but still 5 inch pounds of preload.

What torque is required to continued to compress the crush sleeve and increase the preload? I am wondering if someone rebuilt this differential in the past and maybe never tightened the nut enough to start crushing the sleeve?

Any one have any suggestions? I ordered a new seal so before I try again, figured I needed some advice. Can I pull the front pinion bearing out, pull the crush sleeve out and measure or inspect it to see if it has been crushed?

Any help would be appreciated.

 

[bobs409]

I did 2 of these on other vehicles and just marked the nut and counted the turns when I removed it. I did not replace the sleeve, just the seal and put the nut back on the correct amount of turns.

I have to do my 63 yet, it's leaking pretty good.

 

[models916]

More than likely the pinion bearing caused the worn seal. I would change them both. If just the seal, tighten the nut to the same spot.

 

[MRHP]

I mark nut and pinion with a punch, then reinstall with the nut about .030 tighter than before. It can take a couple hundred foot pounds to compress the crush collar.

 

[Don Jacks]

New bearings go in at 25-30 in.lbs.,used bearings,15-20 in.lbs.While the seal is out,inspect the outer bearing.90 percent of the pinion seals that I replaced during my career were caused by the seal its self.

 

[Jim Sullivan]

Well, it's too late to mark the bolt and count turns, but with such low bearing preload, is it safe to say that the crush sleeve was never torqued enough to start crushing it to get proper bearing preload? If I pull the front bearing and the sleeve out, will I be able to tell? Am I understanding all I've read about crush sleeves that the initial torque of 300-400 foot pounds is just to get the sleeve to crush initially? Then the torque required to tighten the nut to increase preload is much less? Then tighten the nut in small increments until the proper preload is achieved without backing of the nut at all?

 

[Don Jacks]

Jim,I seriously doubt that you'll be able to tell anything by measuring the crush sleeve.Did the rear have any noises,such as a whine? What I did was check the preload before removing the pinion nut,rotate the pinion a few times feeling for any roughness that would come from a failed bearing,remove the seal and bearing,inspect the bearing,replace bearing and seal,tighten the NEW pinion nut a little at a time until the preload was where I wanted it to be,top off the gear oil,road test car.Took all of 30 minutes.If a new nut isn't available,once the preload is where you want it,take a pin punch and punch 3 or 4 places around the shaft to act as a thread locker.

 

[Jim Sullivan]

No noises in the rear Don. I tightened the pinion nut as tight as I possible could with a breaker bar and it stops dead. I still only have 5 inch pounds of preload. I ordered a new crush sleeve for comparison. I am wondering if someone had this rear apart in the past and never tightened the pinion nut far enough to preload the bearings. I can't feel any play in the flange, what will happen if the collar hasn't been crushed and preload is too light?

 

[Don Jacks]

It could cause a pinion depth issue,and the resultant gear noise.As long as this rear has lived to this point,with no issues,and you've got the preload where it was,drive it,you'll be fine.Now if you decide to bolt on a set of small slicks,or drag radials,and participate at your local dragstrips "Test and Tune" night,,,,,,,,,,,,,,,,you might have a problem.

 

[blkblk63ss]

Just to verirfy the question the crush sleeve ,just remove it and see if you can achieve the desired preload with old bearing if you are using old bearing.If you can then the crush sleeve is not crushed. If you can't get preload without sleeve ,something else wrong. By the way I replaced ,,,destroyed,,,,,,two seal's on my 63 ,I did not have proper seal driver .Until I found proper driver third seal went in without being bent.Also put some heavy duty grease on spring in seal to keep spring from jumping out when pounding seal in. PS ,,,,,don't put seal in when you remove sleeve to see if you can achieve preload.

 

[blkblk63ss]

When I installed gear's in my 66 Chevy pickup I had to use two break over bar's with long pipe extension to crush sleeve,s,,in the vehicle. I was amazed how much force it took . I have done a lot of ford's and the sleeve's are not nearly as hard to crush.

 

[Jim Sullivan]

Thanks both Dons. I'll pull the sleeve and see if I can get proper preload and while the sleeve is out, I'll see how it compares to the new one.

Don S, after the sleeve is crushed, how much torque is needed to tighten for additional preload?

It ever thing looks ok, I guess I'll just install a new seal and button it back up and to from there.

Thanks everyone for your input!

 

[blkblk63ss]

Thanks both Dons. I'll pull the sleeve and see if I can get proper preload and while the sleeve is out, I'll see how it compares to the new one.

Don S, after the sleeve is crushed, how much torque is needed to tighten for additional preload?

It ever thing looks ok, I guess I'll just install a new seal and button it back up and to from there.

Thanks everyone for your input!

I just don't worry about torque. Just crush sleeve a little at a time ,checking frequently till you achieve the preload spec. That preload depend's whether you use new or old bearing,as mentioned by Don J. Be care not to exceed spec or you will have to use new sleeve and start over. Just when you get close ,take little increment's at a time. Once you have preload set ,no more tightening is required.

 

[Jim Sullivan]

Well, I pulled the flange off and took out the seal, front bearing and crush sleeve. The bearing is Timken, maybe replaced in the past. It's in really nice shape.
The crush sleeve is diffent than the replacement one I picked up. The old one is split, is that how it was supposed to be?

 

[blkblk63ss]

No split.....

 

[Ishiftem]

No split.

 

[yellow wagon]

No split. Not sure what that's for

 

[Jim Sullivan]

I didn't think the sleeve should be split. I wonder if it happened when it was originally torqued? I don't know how it would have ever torqued down properly and hold the proper preload?

Oh well, glad I pulled it apart and checked. I guess it will be a real pita to tighten the new crush sleeve.

Thanks for the replies!

 

[models916]

Might be somebody's idea of a solid spacer replacement.

 

[Jim Sullivan]

Well, I got it all buttoned up with the new seal and crush sleeve. Ended up with 11 inch pounds of preload. Got real lucky I guess.

I even made up a pinion flange holding fixture that works with an old 1" breaker bar I had laying around the garage.