# Pinion seal



## Layzdude (Jun 14, 2015)

I think I have a leak coming from the pinion seal. Is this something for the shade tree mechanic or should I have a shop do the work? Is an electric impact good enough to remove the pinion nut?

Thanks,

John


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## geeteeohguy (Feb 2, 2008)

Glad you asked. This is a tricky repair. It can be done at home with some finesse and luck. I have about a 75% success rate with these. The trick is to not damage the crush sleeve. If you do, you can destroy the rear end with use. You CAN NOT tighten the nut past where it is now when you re-assemble. So, you need to mark the nut for index, count the threads, and zap it off. Electric should do it. Do not tighten it with that impact gun, however....re-tighten ONLY to your reference mark. If you feel uneasy, a rear end shop can do the job, or a place like 4 Wheel Parts, that does a lot of gear swaps.


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## Layzdude (Jun 14, 2015)

Thanks Guy,

I am planning on removing the 4 speed this winter and was thinking of dealing with the leak also. See how comfortable I feel about it when the drive shaft is out.


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## Pinion head (Jan 3, 2015)

when you get the car up on a lift, and the driveshaft is out, with a pair of thick gloves on, violently push and pull on the pinion yoke and see if there is any fore-aft play, if there is you can disregard ANYTHING anyone suggests to you about marking the nut on the pinion and counting threads, as the nut is removed, to give you a benchmark to install after a new seal. Instead, the pinion has been loose for some time, and best results will come with a pro well versed in differentials, confirming the pinion is loose, and properly correcting, most likely will need a .001 thicker pinion shim, as backlash is tightened up to .010.


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## geeteeohguy (Feb 2, 2008)

Anything Pinion head states about rear ends you can bank on. Great point about the gear lash, PH!


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## Layzdude (Jun 14, 2015)

Pinion head said:


> when you get the car up on a lift, and the driveshaft is out, with a pair of thick gloves on, violently push and pull on the pinion yoke and see if there is any fore-aft play, if there is you can disregard ANYTHING anyone suggests to you about marking the nut on the pinion and counting threads, as the nut is removed, to give you a benchmark to install after a new seal. Instead, the pinion has been loose for some time, and best results will come with a pro well versed in differentials, confirming the pinion is loose, and properly correcting, most likely will need a .001 thicker pinion shim, as backlash is tightened up to .010.



Great bit of info. If that is the case off to the shop.

Happy New Year!

John


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## Layzdude (Jun 14, 2015)

So, I replaced the pinion seal a couple months ago with no issues. It started to leak quite a bit a week or 2 later. Any idea why? I hate to bring it to a shop but I may have no choice.


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## Pinion head (Jan 3, 2015)

Was the surface of the pinion flange, where the seal rides, perfectly smooth, or did it show some wear?


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## Layzdude (Jun 14, 2015)

The flange looked good and I had no issues installing the seal. could the yolk be bad?


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