What is a Pinion / Pinion Seal, and what does it do?

[Rich]

Hi! My mechanic says that my pinion seal is leaking on my 91 Caprice Classic. Normally I used to do most of my own work, but I did not have to deal with a pinion on my old car. Can someone tell me what the Pinion is, and what fluid leaks out of the seal. (I am taking it for granted that it is oil) I apologize if this question seems dumb, but i need to know how serious a failing pinion seal is because i need to do some highway driving next weekend, and i dont want to break down on the side of the road somewhere.

Thanks in advance
Rich "HuMMerMan" C
[email protected]

[Moppie]

Input shaft seal on the diff head, thats all I can come up with. (since the pinion is one of the gears inside the diff).

[jderr48]

your pinion gear is a helical gear that drives your ring gear in your diff. the seal keeps the rearend oil from comming out the diff

[silicon212]

Correct, specifically the pinion is the gear the driveshaft turns, which in turn drives the ring gear which turns the axles on your car. It's a part of the shaft that comes out the front of the differential. The seal is what seals this shaft and keeps the gear oil contained within the diff.

[maxwedge]

Guys everyone replied to a 5 year old thread!!!

[silicon212]

whoops

(slaps own face)