Pinion Seal Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**SactoJim** · 12-05-2007, 05:52 PM

Rearend was built a few years ago and sat for quite awhile before I drove the truck....think it dried out or something cuz it's leaking.

Need to replace and wanna make sure to do it correctly. Isn't there a set "preload" on that and what's the best way to replace this seal. I've done it once before, but many years back and can't remember the details.

Rearend is a factory 12 bolt posi.

Thanks!

Blazer1970 · 12-05-2007, 06:24 PM

Modern seals do not "dry out". It is likely that there is a groove worn into the seal surface of the yoke, and you will not be able to make a new seal work without addressing that issue. A new yoke or a repair sleeve will fix it right up.

**SactoJim** · 12-05-2007, 07:12 PM

Seems kinda odd that would be the case since after I had it rebuilt, I put fluid in it and it sat for a couple years (It was rotated manually many times) and didn't start leaking until I got the truck running and started to drive it around a little.

does the bolt that holds the yoke on have to go back in the exact same position after I replace the seal?

68gmsee · 12-05-2007, 07:27 PM

I replaced the seal on my 68 GMC about 3 months ago. I used an impact wrench to remove the nut (only way to go...) and don't remember any issues with the project. Should be fairly straight forward- pry the old one out and tap the new one in with a large socket or similar object.

I used the impact wrench to retorque it. Went pretty smooth.

12-05-2007, 05:52 PM	#1
SactoJim Registered User Join Date: Oct 2005 Location: Sacramento, CA Posts: 1,970	Pinion Seal Question Rearend was built a few years ago and sat for quite awhile before I drove the truck....think it dried out or something cuz it's leaking. Need to replace and wanna make sure to do it correctly. Isn't there a set "preload" on that and what's the best way to replace this seal. I've done it once before, but many years back and can't remember the details. Rearend is a factory 12 bolt posi. Thanks! __________________ 72 Cheyenne SWB Fleet Nut & bolt frame off in progress...99.9999% - supercharged 383 - 4 wheel discs - relocated fuel tank - My Build Thread

12-05-2007, 06:24 PM	#2
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,507	Re: Pinion Seal Question Modern seals do not "dry out". It is likely that there is a groove worn into the seal surface of the yoke, and you will not be able to make a new seal work without addressing that issue. A new yoke or a repair sleeve will fix it right up. __________________ Tim

12-05-2007, 07:12 PM	#3
SactoJim Registered User Join Date: Oct 2005 Location: Sacramento, CA Posts: 1,970	Re: Pinion Seal Question Seems kinda odd that would be the case since after I had it rebuilt, I put fluid in it and it sat for a couple years (It was rotated manually many times) and didn't start leaking until I got the truck running and started to drive it around a little. does the bolt that holds the yoke on have to go back in the exact same position after I replace the seal? __________________ 72 Cheyenne SWB Fleet Nut & bolt frame off in progress...99.9999% - supercharged 383 - 4 wheel discs - relocated fuel tank - My Build Thread

12-05-2007, 07:27 PM	#4
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Pinion Seal Question I replaced the seal on my 68 GMC about 3 months ago. I used an impact wrench to remove the nut (only way to go...) and don't remember any issues with the project. Should be fairly straight forward- pry the old one out and tap the new one in with a large socket or similar object. I used the impact wrench to retorque it. Went pretty smooth.



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