Pinion seal leak?

[66 bel]

HI
I have a 66 plymouth belvedere which has a 323 sure grip . I had it setup by a reputable guy locally. It leaks from behind the Pinion seal. I changed the seal twice I cannot figure out why it's leaking? It's a mystery . Could it be that it was setup Wrong? Any info or opinion would be great
Thanks Billy

 

[69L48Z27]

Is it leaking from the seal to pinion or outer seal (metal) to the rear housing?

 

[66 bel]

From the front ,the drive shaft side.

 

[Fran Blacker]

I think what 69L48727 is it leaking fron the rubber seal that runs against the yoke? Or is it leaking from the metal part of the seal that goes into the housing. When you replace seal check to make sure there no groove in yoke if it just setup I doubt it. When you remove seal clean the housing where the seal goes into the housing so there is no oil . Add a little sealer around outside of seal, the steel part. Does it make noise when you drive it.

 

[66 bel]

It is leaking from the rubber not the steel. Sorry about that . And it's a new yoke. Is there such a thing as too much gear oil. Too full?

 

[Fran Blacker]

Yes but I don't think that's the problem. Think it holds 2.5 quarts and the seal has oil agaist it all the time. Does the seal have a flange so you can't put it in backwards, seen some without it. You could try a different brand of seal?

 

[66 bel]

Yes it has a flange. It almost seems like the rubber part of the seal isn't thick enough.

 

[RJRENTON]

Gentlemen,
Consider using a "speedy sleeve" to repair the seal contact area on the pinion gear . These repair sleeves should be available at any NAPA outlets or any industrial power transmission firms like Motion Industries . You need to know the OD of the pinion times the length of the seal area. You need to be accurate...measure with OD Mike's. The firm that rebuilt your axle assembly would be able to do this plus install the sleeve. This is a very common method of repairing a worn contact seal fitment. Use a little RTV sealant on the OD of the new seal to insure zero leakage to the carrier. Watch the preload on the pinion bearing. If you over tighten the crush collar , then you will have to replace it. The crush collar sets the pinion bearing preload, NOT the pinion depth. There are procedures in the Mopar stop manual....do not go by a generic manual like Chilton or Motors. Lots of luck with your endeavors....
Cheers,
RJRENTON

 

[Fran Blacker]

Do you have old yoke? Measure diameter of old vs new where seal rides. Did you replace the seal with the same brand, don't think that's a problem but? If it gets desperate they have sleeve that go over yoke where seal rides , but better to figure out why. Maybe someone else will add some other ideas. I see while I was typing another member put something in. I don't think 66 741 or 742 housings have a crush sleeve. Assuming it's a 66, 489 housings used a crush sleeve.

 

[66 bel]

Mine doesn't have a crush sleeve the install kit didn't come with one. Could that be the problem

 

[66 bel]

Yes I have the old yone and I replaced the seal with the same brand.

 

[Fran Blacker]

Do you know the number on the housing? It's on the drivers side of housing, the last three numbers is what everyone uses to I.D. the housing. The 489 uses a crush sleeve. The 741 and 742 use shims to set pinion preload. The person who set it up should know. One problem did any shims stick to yoke when you pulled it out? They can be .003 to .010 or thicker. You would be able to tell crush sleeve or not with yoke out. The shims are 3/16" rings that go over the pinion. If you have it apart 1 picture is worth a 1000 words. i'll see if I can find pictures. Google Mopar 8.75 inch rear differential, pictures and click on images.

 

[SublimeSixpack]

You didn't say, but if by chance it only leaks after you've driven it, perhaps the housing vent is clogged. Just a thought.

 

[66 bel]

It's a 742 . No shims came out with her yoke. It does leak while driving just when it is setting still . Which is strange to me.

 

[Fran Blacker]

You didn't say, but if by chance it only leaks after you've driven it, perhaps the housing vent is clogged. Just a thought.

First pic 741 housing 2nd 742 housing don't have 489 pic. Notice spacer in 741 . 742 pinion is larger no spacer and is the stronger of the two. Duh forgot shims are behind the bearing, geez. Check yokes new vs old??

 

[66 bel]

Doesn't leak while driving just setting still.

 

[Fran Blacker]

No answer, how can you tell? think other member will add some wisdom. I could get an axle in my reat would go in. Asked members. Was told to look to see if side gear splines lined up. Nope, that was it.

 

[66 bel]

I wipe it off clean. And then go for a drive get it back to the garage and it is dry. And leave it for a hour or so and I can see that it has been leaking

 

[Fran Blacker]

I'm out of ideas at the moment. The speedy sleeve is an idea but other members may have other ideas. The clogged vent or maybe it's suck. You haven't said if you have old yoke?

 

[66 bel]

Yes I have the old yoke