61 pinion seal replacement

[Gordon W.]

I'm going to replace the leaking pinion seal on my 61. I have a NAPA part # for the seal (NOS 17727) and read the replacement procedure in my ST-12.

The manual says to discard the old nut and replace with a new nut. My questions: why not reuse the old nut? And my NAPA guy can't find a part for the pinion nut, can anyone give me a part number?

I also read online about checking bearing preload and more, but the ST-12 just says to torque to 150 lb-ft. Is there any justification for making it harder than it is and just torquing to the spec?

Oh, one last question, the manual says to wipe OD of seal with sealer. By "sealer" does it just mean RTV or something different?

[Edward J.]

Re: 61 pinion seal replacement

Gorden, If a new nut is not avaliable, use a drop of blue thread loctite,Also take some old touch up paint and make a line on the pinion shaft and a line on the flat of old nut. so when you tighten the nut you be where it was originally. and yes RTV smeared on the metal outside lip will aid in the sealing. Also I take some RTV and put some on the splines of the pinion flange, this keep the 80w90 oil from traveling up the splines of the shaft.


Since you'll be using the old nut don't worry about bearing preload. just tighten the bolt to you marks you make on the nut and pinion shaft.

[Gary R.]

Re: 61 pinion seal replacement

I wrote this several years ago for the 63-79 seals, it may help you. The only thing I like to use #271 red on the pinion nut. Once it's cleaned with acetone and setup with the 271 red it will be locked tight and should not loosen unless heat is applied.

http://www.digitalcorvettes.com/forums/showthread.php?t=76719

[Gordon W.]

Re: 61 pinion seal replacement

Wow! That's a keeper link, thanks.

Just one follow-up question, and yes I read the whole thread. The red stuff on the new seal is RTV?

[Joe L.]

Re: 61 pinion seal replacement

Wow! That's a keeper link, thanks.

Just one follow-up question, and yes I read the whole thread. The red stuff on the new seal is RTV?

Gordon-----


The GM nut is discontinued. I can't find another supplier but there must be one. However, you can just do as others have mentioned and use red Locktite on it. The ST-12 might even have so-instructed but Locktite had not been invented yet when it was written.

Most of the seals available nowadays already have sealer applied to the outside perimeter of the seal frame. Usually, it's red or green in color. So, if yours already has the sealer, you don't need to apply any. If not, you can use RTV. Do not use red Locktite for the seal.

[Clem Z.]

Re: 61 pinion seal replacement

make sure you put a little rear gear lube on the yoke when you install it into he seal to make sure you do not have a dry startup and burn up the seal

[Stephen R.]

Re: 61 pinion seal replacement

That nut is a different kind of nut. I looked all over for one at Carlisle and found a vender who carried them ( I can't remember the name unfortunately). The nut had a unique thread count and it's not quite round at the outer end but appears to be slightly oval. I was told this was the "locking" part to lock the nut in position.

[John H.]

Re: 61 pinion seal replacement

Richard Fortier probably has that nut - if not, he'll know where to get them.