'62 pinion seal and cover gasket

[William F.]

My mechanic and I are going to replace pinion seal and cover gasket on my '62's posi diff tomorrow. A few questions: CSM says use new flange nut, is this necessary? Fel Pro rear cover gasket is a thin rubber like material. Is any sealer needed? How about on pinion seal ? CSM just says to soak in oil for 10 min. before installing.
Thanks

[William F.]

Re: '62 pinion seal and cover gasket

How 'bout it some of you driveline experts? Want to do it right.

[William F.]

Re: '62 pinion seal and cover gasket

How 'bout it some of you driveline experts? Want to do it right.

[Larry C.]

Re: '62 pinion seal and cover gasket

I believe that the Corvette Servicing Guide ST-12 covers this, or any of the other Chev repair manuals of the 1960s.

[Leif A.]

Re: '62 pinion seal and cover gasket

Just as an aside, I recently replaced my pinion seal and discovered the cause of the leak were some very fine ridges on the input shaft on the driveshaft. Had to have the driveshaft input shaft machined smooth to prevent future failure.

[Tom P.]

Re: '62 pinion seal and cover gasket

I PRESUME you do know that the axles have to be pulled so that the center section can be removed to replace the gasket.
I've been working on and rebuilding these rears (same as 55-64 pass car) for 45+yrs.
You CAN use sealer on the gasket if you like, I do not use any.
NOOOOOOOOOOOOOOOOOO, you do not need to install a new pinion nut---------------unless yours is junk.
The old, ORIGINAL pinion seals had leather for a seal, so, soaking in oil was appropriate---------------but NOT with today's seals. Simply wipe a little oil on the seal where it contacts the pinion yoke.
CLEAN, CLEAN, CLEAN, CLEAN, CLEAN the area where the seal fits into the rearend center case, the pinion splines, and the INSIDE splines of the yoke.
I like to apply a VERY, VERY thin layer of gasket sealer around the seal where it fits into the case (I use Permatex sealant which comes in a can with a brush in the lid).
CAREFULLY and METHODICALLY tap the seal into the case.
HEAVILY coat the inside splines of the yoke with sealant (so that oil won't migrate along the splines and leak around the nut).
Coat BOTH sides of the thick pinion washer and install the nut.
I put this together a few years ago in the 61-64 section of Chevy talk. Some of the pictures may be of some help.
http://www.chevytalk.org/fusionbb/sh...hp?tid/223802/

[Gary R.]

Re: '62 pinion seal and cover gasket

Tom is the guy for these diff's for sure. I do the 63-79's, same theory. I mentioned in your other thread you can reuse the nut with Loctite and staking. I switched over from Permatex #2 to their Permashield for the yoke splines. I had very good luck with the #2 for many years but the blue permashield works great and by now should be available in most parts stores now. Pack the spring on the seal with grease and I coat the seal with it too.

[William F.]

Re: '62 pinion seal and cover gasket

Thanks, Tom, but gasket I'm talking about (in addition to pinion seal) is the gasket for the rear diff cover. You don't have to pull axles to service this gasket, do you?

[Tom P.]

Re: '62 pinion seal and cover gasket

ONLY 53-55 rearends had a removable cover. The rearend cover of 56-62 cars was welded to the axle housing.
Now, IF you do have a rearend in your 62 that has a removeable cover--------------THEN IT IS NOT A 62 AXLE HOUSING!

[William F.]

Re: '62 pinion seal and cover gasket

Tom,
You're exactly right.On closer inspection my rear cover on my '62 is welded to case. My problem was ASSuming that the oil I saw on back of diff was coming from a"cover" but all is apparently coming from bad pinion seal. Thanks for tips on taking care of that.

[William F.]

Re: '62 pinion seal and cover gasket

Tom, read your article in Chevy Talk. Question: You say torque pinion nut to 25 in. lbs; CSM says "150-190 FT LBS";Am I missing something?

[Tom P.]

Re: '62 pinion seal and cover gasket

Yes, you are missing something. There is NO torque spec for tightening the pinion nut. MASSIVE torque is required when installing a new crush sleeve, to get the sleeve to start compressing. Once the sleeve is crushed and begins applying preload to the pinion bearings, THEN, the correct amount of preload is determined by using an INCH/POUND torque wrench. With NEW bearings, the torque reading (as you turn the pinion with the torque wrench) should be about 25in/lbs. With USED bearings, the torque should be about 5in/lbs.


MANY, MANY, MANY "experts" insist that a new crush sleeve should be installed when replacing the pinion seal. Since this is a public forum, I'll not use the language that I feel is appropriate, and I'll just say that is not absolutely essential to replace the crush sleeve in MOST, repeat, MOST cases. I DO NOT claim to be an expert on these early rears, but I have been rebuilding them for over 45yrs, as well as converting non-posi rears to posi.
So, with that said, once the new seal is installed, and the yoke, washer and nut is back on (presuming you are retaining the used bearings), tighten the nut until it is TIGHT. Spin the pinion to see how it feels. Now, use something to securely hold the yoke (a GIANT pipe wrench works fine). Put some torque on the pinion nut (50-70lbs). Spin the yoke again. If it still feels the same, put some more torque on it (80-90lbs). If you now feel a VERY SLIGHT resistance to turning the yoke, QUIT. You're done. What you have done is to apply a very small amount of preload to the pinion bearings. If you need further information, or want to contact me personally, tparsons6@cox.net or 405-745-8383.

[William F.]

Re: '62 pinion seal and cover gasket

Tom,
Thanks for all the help on this forum and by phone. Using your tips, my mechanic worked with me and lining up old pinion nut with pinion shaft as you suggested, seems like new seal and sealer cured the problem. No runs, leaks, or errors so far.

[Tom P.]

Re: '62 pinion seal and cover gasket

Sounds GREAT!