cyberkill

Man, I thought I was so close to finishing this damn project...and then this happens! It hasn't even touched the ground yet, it's still on the 4 jackstands its been on since the beginning of the project. After filling up the diff with gear oil, I'm seeing a leak of about the size of a saucer or small plate every day (call it every 12-16 hours).

So, I have done my research, and I know about the 2 different kinds of pinion seals. I have a 2001, and so I need the new one. I also verified this just by the fact that mine looks like newer design AND the newer design hugs the yoke securely, where as the old design (the one I got with my kit) is super tight, that it makes it hard to move.

This is the one I have:
http://www.rockauto.com/catalog/more...558&cc=1379976
(FYI: the Timken one with the same part number is the old design)

Is it even possible to improperly install a pinion seal? I used a rubber mallet and a seal driver to drive it into the housing, and I double checked around to make sure it sat flush with the housing (it's not in at an angle, and there aren't any gaps). I mean, is there really much more to do than that? Once you put the yoke in and tighten the pinion nut, even if you didn't tap in the seal all the way, wouldn't that tighten it anyway?

Has anyone had experience with the National brand one as opposed to the GM one? Does GM even sell the right seal anymore? If they do, what is the right GM part number? I've seen GM# 26026792 floating on these forums, but doing some searching, I've found that GM 12471523 is also mentioned, and the latter looks more like the design I have. Can someone clarify for me?

I know I have to take EVERYTHING out...and I'm probably going to go solid spacer this time instead of crush (that was a HUGE PITA!). I just wanna finish this project. HELP!

cyberkill

Bump. Any help guys?

cyberkill

Ok, perhaps a little more information.

If I look at the spot where the pinion seal goes into the housing, it's try. The leak is not coming from oilseal and housing contact. After I dry it up a bunch and inspect the leak later, it seems like it's coming from behind the yoke, and then collecting at the bottom of the little cup the yoke makes over/on the oil seal.

My guess is then it's from the little rubber seal it makes with the pinion itself. Is that possible?

LFSADRG

iTrader: (1)

Interested in knowing more. Replaced seal earlier in the year and now there is a small leak. Used black RTV and thought I had the rear sealed fine. Not sure what brand seal I used.

01ssreda4

iTrader: (96)

Sometimes seals just leak. Try again and it will probably seal. Main things are don't deform it when tapping it in, and the metal surface on the yoke is smooth and groove free. If that checks out you should be good. I like to lube them on purpose so they aren't installing dry, and I like a thin layer of ultra black rtv between the outer metal ring and the rear end housing just to be safe

cyberkill

If I had to guess, it's leaking through the center of the oil seal where the pinion goes through. Not sure how, but you mentioned not deforming the seal.

Not sure if this counts, but I used a seal driver (per a writeup and a video I saw) to seat the seal. The driver is just a solid disc, so naturally, while it presses on the edges of the seal to drive it in, it kind of smothers the rubber part in the middle of the seal where the pinion goes through....which also happens to be where I suspect the leak is coming from.

I guess I thought if this thing can sustain billions of pinion rotations through it, a little smothering won't be so bad. Am I wrong?

And if that's the case, what's the best way to drive that seal in? Can't use the seal driver bc it compromises the middle seal. Can't just use a mallet on the sides, bc it'll probably bend the outer metal lip back. Do you use an old front pinion bearing maybe?

LFSADRG

iTrader: (1)

I used a piece of flat wide piece of wood to tap the seal in. The car is mainly bracket raced so possibly the numerous launches may have cause the seal to distort. The leak is very minimal but still a leak.

01ssreda4

iTrader: (96)

You want to use a socket, pipe, or simply tap around the edges. A solid flat piece would by incorrect or not as good in this instance. Don't know if you deformed it but why risk it. Tapping softly around the perimeter will not deform it.

cyberkill

Ok thanks. I'll give that a shot tonight.

cyberkill

OK, so looks like I was right. The oil is spilling from the hole where the pinion goes through. Now, in this picture, it's really flowing, but when the gap between the yoke and the housing was about 1/4 of what it is in this pic, it was dripping fairly rapidly, but I could still see that oil was just pushing through the gap like the gap was slightly too big or something.



Now, I have a 2001, and the oil seal that came out of my car looks like the 2nd generation oil seal, as far as I can tell. I mean, when I tried the one that came in my Motive gear set (which was the older model seal), I could barely even get it around the pinion, so the yoke would have definitely not fit through it.

The other thing I've read is that an oil leak can come from a groove in the yoke. Well, I know this counts as a "groove," but does the groove have to be above/below a certain spot in order for it to cause a leak, and would it cause a leak this bad? If I drag my fingernail down that little shaft, it does stop on the groove. How is it I've never had a leak before if this is the same yoke?

01ssreda4

iTrader: (96)

The two yokes are different. The seal either fits or its blatantly wrong. Once you've determined you have a snug fitting seal (test fit on the yoke before you tap it into the housing) then you can rule that off. If the seal fits the yoke properly, then either the yoke is fucked, or once installed its not sitting centered in the housing for whatever reason. You should not be able to snag your nail on the sealing surface of the yoke (where the seal rides) if you can then I'd replace it.

cyberkill

Since I could snag my nail, I just bought a sleeve. Hopefully this is the right part number:

cyberkill

Apparently, that's the wrong one. Another $20 down the toilet.

Does anyone have a part number on the sleeve that goes around the pinion yoke? This is for the 2nd generation yoke.

chrysler kid

iTrader: (14)

My new seal was leaking so I used the spring thing that is tucked under the rubber part of the old seal on top of the new spring seal retainer.

Mine was also leaking from the rubber around the yoke but immediately stopped once I put that second spring ring on the rubber part of the seal.

My car is a 98 btw

chrysler kid

iTrader: (14)

Just saw your full size pictures and you're using the wrong seal, or have it on backwards. On my car it sits flush and the rubber points into the rear end not the yoke

cyberkill

The oil seals are designed differently before 2001 and during/after 2001, mainly because of the yoke. In 2001, they basically put this...thing...on the yoke that increases the OD of the yoke shaft, so the oil seals had to change too. If you look at the first picture (the portrait picture), the little flange coming out of the housing (left side of the pic) is the oil seal fully seated. You can't put it in the other way.

The 2nd picture isn't the oil seal, but it's the yoke with that...thing...on it starting in 2001.

01ssreda4

iTrader: (96)

You're correct, he doesn't know what he's talking about or looking at.

silverWS.6

iTrader: (1)

Any more updates on this? I'm having the same issue with a leaking rear. It's leaking exactly the same way as you described in your second post. Did the national seal work out for you?

01ssreda4

iTrader: (96)

^^^what seal is on your car?

silverWS.6

iTrader: (1)

The GM one, 2nd design.