Differential pinion seal
Thread Starter
4th Gear
Joined: Jul 2016
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Differential pinion seal
I have a corvette differential. Best I can tell it was on cars from 63 to 79. The differential came on the 34 Ford Roadster I purchased last fall. I have to replace the front pinion seal and was curious to know any precautions I should be aware of.example, breaking the nut holding the yoke and is there a preferred manufacturer for the seal itself. Thank you
Race Director
Joined: May 2006
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Mark the nut in relation to the pinion and count the number of exposed threads so you can install the nut exactly in the same position. Lubricate the surface of the seal that is in contact with the pinion and apply some RTV to the outside of the seal.
Safety Car
Joined: Jul 2005
Posts: 3,698
Likes: 833
From: WI
A lot of guys zip them off with impact wrenches, but if you get a really tight nut it seems to hammer on the gears. I made a holder out of a piece of 3' long 1 3/4" x 1/4" bar ....and a couple holes on the end (and welded some 'ears' on the end to clear the socket). On several GM manuals they advise such a holder. I've drilled mine to different vehicles I've owned over the years, it's come in really handy. If I do the job on a vehicle I just let the bar rest on the concrete. If on a bench the bar can rest of the benchtop.
Here are the steps out of a full-sized car GM manual for pinion seal replacement (just happened to have the manual nearby):
1) Put a mark on the: Nut, Pinion shaft, Yoke (to realign after the job)
2) Remove nut (using a holding bar) and remove the Yoke
3) Remove old seal (don't score the bore if you're using a sharp puller
4) Inspect shaft for burrs etc. Also not a bad idea to inspect the bearing and race too
5) Install new seal (I recommend using a GM seal - they're usually better and have an extra lip)
6) Lube yoke and install according to the marks
7) Tighten nut ..and go 1/16th an inch beyond your original marks to achieve preload.
,
Here are the steps out of a full-sized car GM manual for pinion seal replacement (just happened to have the manual nearby):
1) Put a mark on the: Nut, Pinion shaft, Yoke (to realign after the job)
2) Remove nut (using a holding bar) and remove the Yoke
3) Remove old seal (don't score the bore if you're using a sharp puller
4) Inspect shaft for burrs etc. Also not a bad idea to inspect the bearing and race too
5) Install new seal (I recommend using a GM seal - they're usually better and have an extra lip)
6) Lube yoke and install according to the marks
7) Tighten nut ..and go 1/16th an inch beyond your original marks to achieve preload.
,
Last edited by Mark G; Feb 11, 2020 at 05:13 PM.
Tech Contributor
Joined: Aug 1999
Posts: 15,179
Likes: 3,999
From: Connecticut, USA
Here is a thread I wrote 13 years ago on doing the job.
https://www.digitalcorvettes.com/thr...acement.76719/
https://www.digitalcorvettes.com/thr...acement.76719/
