Technical Tri 5 Chev pinion seal.

My brother has a 57 Chev rear end in his 50 Fleetline.
The pinion seal has started to leak a little and he wants to change it.
Can we do it without pulling the pumpkin?
What's the best way to do it without screwing up the crush sleeve and pinion depth?

 

Pull the pumpkin, take it all apart, install a new crush sleeve.

Or do you want to know the lazy way that may or may not work?

 

I figured that was the case, but I'm curious about the lazy way.

 

Pull the pinion yoke, replace the seal, replace the pinion yoke, and torque it to original specs.

Your not gonna change the pinion depth. And the original crush sleeve shouldn't change with the same torque. You might use a new pinion nut.

 

The problem I usually run into on the old Chevys is that the nut got loose, and the bearings spun, and the crush sleeve is worn. When you tighten to the original torque specs with the worn sleeve, the pinion bearing preload is way too high. Sometimes the wear is so bad that the yoke is worn, and when you torque it down, there's still play in the bearings, because they yoke bottoms on the pinion stem.

You can do it however you want...

 

The diff was rebuilt about 15 years ago, it was in my dad's 51 hardtop.
It saw very little use before we swapped it out for a 10 bolt, it's been sitting in my brothers shop until we put it in his car last winter.

 

This what I did on my 55' 16 yrs ago and hasn't leaked a drop since.

 

if it is not much of a leak leave it alone---if it is too much try the lazy way it usually works...

 

Mark the nut on the pinion. Pull the yoke, replace the seal, use offset seal if you can get one. Tighten the nut with red loctite to the same spot it was.

 

Wish you luck

 

Well, I gave my brother the options, he chose the lazy way.
We changed the pinion and trans seal, put it back together and ran it on the jack stands.
It seems fine, I guess he'll know for sure when he takes it for a proper drive.