12 Bolt Pinion Seal Leak

Yes it can be changed without removing the rear or affecting the pre-load.

Read these posts, they will answer your question.

http://www.camaros.net/forums/showthread.php?t=60931&highlight=pinion+seal

http://www.camaros.net/forums/showthread.php?t=38375&highlight=pinion+seal


Mike

Check the pinion bearings. Many times a pinion seal leak is caused by a bad pinion bearing.

Is there a way to get a good check of the bearings without taking them out of the diff.? Thanks for your advice...sounds like you have done this many times before?

Check the pinion for up and down or in and out movement. Any movement other than rotation is bad. If it feels good and tight then the bearings may be fine.

I recently replaced the pinion seal in my GM truck. It was a simple job. Mine was cut by "of all things" a plastic bag. It twisted like a rope around the pinion and put a nice cut in the seal. A couple days ago I dodged a "plastic bag" as it drifted across the road in front of me. My Son thought it was funny 'til I reminded him what happened the last time I ran over one of those deals. :sad:

Going to help (my not so mechanical) brother do pinion seal on his 72. Basically what I have read is straight forward. Is there any differances in year, make, for the rear end hardward? Has been a very long time since I have done one, just want to be clear before I jump in. All advise is very appreciated. Thank you to all.

The pinion seal is the same on all of the 12 bolt rear ends from '65 to '72. Just be carefull about how far you drive it in. The car pinion seal is no longer available and the seal that you get today will be for a truck 12 bolt. Sometimes if you drive it in all the way the seal will contact the outer pinion bearing, which will cause the seal to fail again.