The pinion seal on my IROC is leaking. It's an 85 IROC with the stock 10 bolt. To replace the pinion seal my service manual shows a GM puller being used to separate the yoke from the pinion. Is a puller really necessary or will this thing usually come off without drama once the nut is removed? If I do need a puller, has anybody used a more generic puller or is the GM part required?

 

you need to make the nuts and count threads ect to mack sure the nut goes back on with the same preload as when it came off.

With the nut removed, mine came right off, maybe a tap with a hammer if its stuck a bit. No special tool required

 

It's crucial that you get the nut tightened back EXACTLY where it was before you removed it. I usually count how many threads are sticking out of the end of the nut, then take a hammer and a sharp chisel to put a corresponding mark in the nut and the pinion threads. Yeah, a few love taps with a hammer will usually get the yoke off. Make sure to smear a small amount of gear lube on the rubber lip of the new seal before you put the yoke back on. If you don't, friction can burn the lip and cause it to leak again. Also, a 2-1/4" to 2-1/2" exhaust pipe adapter from the parts store makes a great tool to drive the new seal in. It clears the end of the pinion shaft, drops right into the metal recess of the new seal, and you just use a hammer to tap around it and drive the seal in place.