Hot Rods Ford 9" leather pinion seal

Before I put the Ford 9" in the car I had the 3rd member serviced with a new pinion seal which was obvious the old one leaked. I then learned they came with a leather pinion seal which mine had and it was replaced. Not shortly after putting some miles on it, its already leaking...slowly but leaking. Is it possible to put a newer type pinion support that uses a standard seal to get away from the leather seal, or do I need to hunt for an entirely newer 3rd member?

 

yes, you can change the pinion support. But you'll need to set the pinion depth, to get the correct ring and pinion contact pattern.

There are some other possible places for it to leak, such as the yoke being worn, and the splines at the yoke not being sealed properly

 

Hmmm, never seen a 9" with a leather seal. I'd look for a 'cross' into a 'conventional' seal first. And what Jim said above...

 

Yup you can get a neoprene seal for any 9 inch, even the early ones with the large diameter seal. C/R (SKF) makes for either size seal. National does still list a leather seal for the 9 inch with the large diameter seal. #6930. I'm guessing you don't want another one of those though. And yeah, what Jim said.

 

One thing I remember about the leather seals is you need to soak them in a lighter oil before installing them or they will leak.

 

A leaking seal is usually a symptom of something else wrong. Leather seals have been employed for a long while without issue.Our friend doesn't tell us if there are issues with the seal surface of the yoke or condition of the pinion bearings. Are there vibrations from the driveline? So, changing to a different seal arrangement may still end up with a leak.

 

I recently had a pinion seal leak on my roadster. Bought a seal and slid under the car. I noticed the leak came out of the splines in the center of the yoke! I pulled the yoke, sealed the splines and also replaced the seal just to be sure. I used an anarobic sealer and voila, no more leak. It was bleeding down the pinion splines and past the nut.

 

The early 9" rears used leather seals. I have a rear from a '57 ranch wagon (big bearing housing) and the pinion seal is a "one off" leather seal. They went to a more modern type seal in '58-'59 or there abouts.

 

I used one in an early 1950's diff and replaced it sometime after a bearing failure with a similar leather seal.
The guy in the store told me they are know as RAWHIDE seals.
Sounds real western to me...

 

actually CR seals are Chicago Rawhide. It's back east, from here.

 

I’m not having any other issues besides the leak. Thanks guys, I’ll look into a newer seal and support to accommodate it. I’d just like to be as foolproof as I can to fix it.

 

Make sure you have a vent or breather on the housing. I seen guys making "perfect" show cars not have them and when they start using them, s--t happens...