Thread: Changing rear pinion seal

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The pinion seal is leaking in my daily driver, a '93 Caprice. I was pricing seals at Autzone and they had a link that showed how to change it. Looked liked it was not too difficult. Any problems/headaches that could surface during the job? Any tips? Thanks, mrbigg.

I have had luck in the past with putting a witness mark on the pinion nut and shaft so that you can return the nut to approxamatly its original bearing load.
The proper way would be to take it all apart and set the rotational torque in inch pounds at the correct setting for used bearings ,but the mark and return method works pretty well for me.
You will want to make shure to back up the pinion ,not just throw a wrench on there and snap ring teeth off,there should be a place to get a wrench on there to hold it and leave room for another wrench to take off the nut.
The same principal with removing a plumbing fitting ,back it up.i had to use a large pipe wrench on the last one to back up the pinion for the nut removal.
Also at a minimal use blue loctite when re-installing the nut ,you should actually use a new nut too and i think it calls for red loctite on a new nut.........old nut is not recomended for re-use.

mrbigg,

There are two different pinion installations that are commonly used....shims and crush sleeves. The shim style setup sets the pinion depth (relative to the ring gear) by using shims....if you tighten the pinion nut too tight, just right, or not quite enough, the pinion depth stays the same because the shims are setting the spacing.

For the crush sleeve method, instead of shims, there is a tube that "crushes" or collapses as you tighten the pinion nut...if you go too far, the crush sleeve becomes too short and allows end play on the pinion. The crush sleeve was invented to allow easier setup at the factory since they dont have to measure, remove the pinion, add shims, reassemble, etc. Instead, they torque the pinion nut until the proper pinion depth is met.

Unfortunately, a Chev has a crush sleeve. Unfortunately, making a mark on the nut doesnt work since the nut is a deformed thread nut and is usually replaced with a new nut. I know someone (very close to me) who has reused the nut by first scribing the witness mark on the nut and the pinion (not the housing!!) and disassembled the nut. After replacing the seal, the nut was replaced and the marks aligned. I....er he, used Loctite to assure the nut stayed tight.

If you use a hand wrench instead of an impact, there is no danger of hurting the teeth...if you can put constant pressure on the nut with an 18" breaker bar and your arms, you cant hurt the gears...at least a normal person cant.

If in doubt, ask for a quote from the Chev dealer to replace the seal....

mike in tucson

Thanks guys.