Relatively new owner of a '78 L-82 and I'm trying to change the front pinion seal on the differential.

Tried for 4 hours and cannot get the damn pinion nut off.

Is there anything I'm missing, or has anyone else had a hard time getting this nut off?

Any suggestions?

Help!

 

I did 2 of these about a month ago and a large impact quickly removed the pinion nut. I use a snap on 1/2 inch drive impact and both nuts come right off. It might not be the seal but the diameter of the yoke is wrong. We use a special sleeve pressed over the yoke to fix this problem.
Gary has the sleeve and could give you a part number or even a good price on one.

 

you gave to make a tool to hold the yoke and then use an impact to get the nut off, it is Very tight. A flat steel bar 2" wide and 2' long with 4 holes drilled in one end to match up with the U-Joint strap holes and a hole in the middle of them for the impact socket to go thru for the nut will get you there. I am sure there is a store bought version out there.

Ahh, what Norval said

 

The impact wrench is your friend.

 

We are going to try to use an impact wrench with an extension this week. Does depressing the brakes provide enough resistance to break the nut loose without having to make a tool or purchase one?

Norval-the rear end is bone stock, so I don't see how the yoke could be the wrong one, but I am a novice to this and am not rejecting your suggestion out of hand.

I also thought about drilling the nut off by drilling on either side of the nut with increasingly larger bits, but that would be a last resort.

Thanks for all the quick responses!

 

You should be able to hold the pinion with your hand and the impact will take the nut off.

Don't drill it.

 

Thanks BC.

Whenever I see that icon I just have to laugh. I feel like I'm 10 years old and have just broken the garage window (again).

 

I never used anything to hold the yoke. Nothing. The impact just spun them off in seconds without touching anything else. I did one with Carguy4sure and he was amazed how simple everything came apart or went together. I use the impact to remove the u bolts for the driveshaft also.

 

yes the brakes would work but the impact needs no help.
The yoke is marginal in the seal to begin with. The finish on the yoke is also important for a good seal. I found with the yoke off on the bench, cleaned and polished that a new seal just slipped over the end hardly touching the yoke, this is a stock yoke. The little sleeve that slides over the yoke has the proper finish and is about .020 bigger so the seal fit is really nice.
Gary knows alot more about this then I do. While I posted on it Gary jumped in with alot more information.

 

If you are new to vettes and this job in particular I can offer a few thoughs to think about.

First a large set of channel locks or pipe wrench will hold it to break the nut loose. Before you do that you have to be sure to mark the nut location to the pinion end. It is important to get the nut back in the same location to maintain the pinion bearing preload. Also, if you are using a impact to install the nut you'll have to be careful not to over crush the inner sleeve. They compress rather easily with a impact gun after the initial crush is made. Be sure to check the seal flange to housing gap and use #2 on the yoke splines.

Norval was referring to the pinion yoke OD that fits against the seal ID. The yoke surface is like a harmonic balancer shoulder in that it can be grooved or pitted. I have the speedy sleeves that press over the OD of the yoke to form a better seal. The last one I did was a very good original differential but the yoke surface was pitted too much for me. The sleeve, although not cheap($30), solves this problem.

Use red loctite #271 on the nut too, clean it off first with brake cleaner.

Good luck
Gary

PS Norval is certainly qualified to answer these posts, don't let him fool you!LOL