What are you using for 8 3/4 pinion seal?

-
Mike69cuda

Mike69cuda

Mopar Moron
FABO Gold Member
Joined
Jan 2, 2018
Messages
3,482
Reaction score
3,271
Location
Kansas City
I replaced my pinion seal on my 742 case 8 3/4 rear end awhile back and it is leaking again. I took out a leather seal and replaced it with a new leather seal.

Is there a better seal, or a trick I don’t know?
 
Is the yoke groved? Check rockauto for the sleeve kit.
 
65TerrorCuda said:
They can leak through the pinion spline and out the nut too according to what I heard. I siliconed the splines on mine and no leaks there
Click to expand...
I used Permatex High Temp Sealant wiped it on the insides of the pinion splines of the yoke before I slipped it on. I think that was part of the instructions in the Factory Service Manual.
 
Mike69cuda said:
I replaced my pinion seal on my 742 case 8 3/4 rear end awhile back and it is leaking again. I took out a leather seal and replaced it with a new leather seal.

Is there a better seal, or a trick I don’t know?
Click to expand...
when you do find these antique leather seals and you want to use them , you are supposed to soak them in the oil used in the application e.g. rear axle fluid for differential seals and engine oil for rear main side seals or timing cover seals before installing the seal , this allows the leather to expand . installing it dry will damage/glaze the seal and make it leak ,. however use modern rubber seals such as Timken 7216
 
john-9 said:
when you do find these antique leather seals and you want to use them , you are supposed to soak them in the oil used in the application e.g. rear axle fluid for differential seals and engine oil for rear main side seals or timing cover seals before installing the seal , this allows the leather to expand . installing it dry will damage/glaze the seal and make it leak ,. however use modern rubber seals such as Timken 7216
Click to expand...
Yeah, I did the soaking in oil & thought I was pretty careful putting it in. Drives me crazy when I replace one leaking seal with another leaking seal. But now I have a lift which makes it so much easier.

I think the rubber seal & the sleeve will solve my problem. Along with checking the vent
 
Look at the pinion shaft, I wouldn't use a sleeve unless I saw an actual problem with the seal surface
 
Got my yoke off and it is a little grooved. Can feel it with a fingernail pretty easy.

Ordered the sleeve and the seal from Rock Auto and I got another one with a leather seal! Ouch! Thought I ordered the rubber one.

Going to look again & see if I can find the rubber one.

What does everyone use? The Leather? Am I wasting my time chasing the rubber one?

The sleeve looks to be a press fit. The diameters are about the same. They provide a tool to install it with. How do I install it, do I need to lubricate it or do I use locktite? I have never done a sleeve before.
 
i use Timken 7216 or SKF 18912 or Rat 6103 from Summit racing all these are rubber seals for the 742 case ,, which seal did you order ,, the sleeve is hammered on over the yoke surface using the install tool supplied ,, if you need more info go to the speedi-sleeve website and it will show installation or U-tube it
 
Watched a couple you tube videos for the sleeve it went on easy. Used the leather seal because I already had it and didn’t want to wait for another one. Can’t really return little stuff to rock auto because of shipping. We’ll see how well it works.

Thank to everyone for all the advice!
 
I wouldn't use a leather one for one simple reason. There's no telling how long they've been on the shelf and they are probably dried out. Modern rubber seals are simply light years ahead. Get this one and be did wif all dat, yo.
www.doctordiff.com

Mopar 8 3/4" (8.75) Pinion Seal for 742 or 741/489 Case

Premium quality Mopar 8.75" pinion seal. Choose 742 or 741/489 case
www.doctordiff.com www.doctordiff.com
 
You must log in or register to reply here.
-

Back
Top