Pinion seal - which side is which?

[cattlerepairman]

I need to replace a pinion seal and looked at the replacements. They look different than the original seals that are in the axle (dare I say..."cheaper"). I can't figure out which side faces the oil side.

Here is a pic of the seals from a vendor:
http://www.rockwelloffroad.com/index.php?route=product/product&product_id=70&search=pinion+seal

I notice that on one side there is a "gap" between the metal seal housing and the rubber seal (the right seal in the pic) which I would believe to face the oil side. Any ideas?

 

[doghead]

It should have at least 2 lips, facing opposite directions. It could have more.

You'll need to see it to tell.

I would guess the metal surface would face out.

 

[TGP (IL)]

It's really hard to see, for me anyway.

The right picture does look like it would face the oil supply.
Agree with your thinking about the gap facing the oil.

Double lip deals can be hard at time to figure orientation.
Tom

 

[gringeltaube]

In reference to those pics: right and left is one and the same... showing the outside, only. No pics from the inner side to be seen there.

No matter what style and if single or double lip, normally an oil seal is installed this way...(diagram, below...)
Exceptions of the rule do exist: e.g. the drum seals on the military Warn winches.

, regarding our pinion seals: there is enough room to install two 3/8"-wide single-lip seals, side by side; the outer one with the lip facing outward.
All of my axles I have always assembled that way. Best results...

 

[rustystud]

The picture shows the "outside" of the seal. The inside will have a small steel spring around the rubber seal.

 

[cattlerepairman]

The picture shows the "outside" of the seal. The inside will have a small steel spring around the rubber seal.

That's what the old seal looked like; the new one does not have a steel spring. ***EDIT: THIS IS BULLS*** AND MY MISTAKE: IT DOES HAVE A SPRING****

 

[doghead]

MAybe you can contact where you bought it and see what they say.

 

[rustystud]

That's what the old seal looked like; the new one does not have a steel spring.

Really !? Very interesting.

 

[gringeltaube]

That's what the old seal looked like; the new one does not have a steel spring.

... Then don't buy it!




The shaft Ø in this case is 2.375" and the bore, 3.350".
Here are a few more "modern (double-lip) seal numbers for that application:

• TIMKEN: 412119
• SKF: 23702

G.

 

[cattlerepairman]

This bugged me enough to do a comparison.


Here is the TIMKEN/NATIONAL 412119 seal made in the USA: it is a double-lip seal with a steel spring on the inner (oil) side.




Here is the NewStar (or similar) 7521241: this is also a double lip seal with a steel spring on the inner side. The inner side (oil side) is the side where the seal carrier halves are joined and where the spring sits.



Width comparison:




The TIMKEN/NATIONAL is narrower.


I hope this will help when you need to figure out your pinion seals!

 

[jimm1009]

Hello there fellow MVers.
I have a question and comment on the seal mentioned above. First I have to add that no, I have not yet changed one of the pinion seals but I do need to as I don't have real leak but just a seep at this time.

A double lipped seal is usually used in an application where there are oils on each side of the seal and this is designed to keep them from mixing or transferring.
With this said, if the outer lip is not kept wet by oil or grease it usually wears a groove in the shaft that rotates within it.

Is this seal really supposed to be double lipped or is the original design a single lip?
I only mention this as these parts are getting more expensive and harder to find.
A speedy sleeve can repair or prevent a wear groove in many applications and my M38 has a few of them riding around helping to keep oil where it needs to be.

jimm1009 (Jim)

 

[cucvmule]

Sound Advise, the sleeves can save a bad wear surface or "prevent" one from happening. The problem with the sleeve is that the seal is tolerance made for original size. However the seal if need be can always be replaced at a shorter interval as needed.

 

[gringeltaube]

.... A double lipped seal is usually used in an application where there are oils on each side of the seal and this is designed to keep them from mixing or transferring....

Not in this case: The one referenced above is only a "so called" double-lip seal, and both lips are not identical. The outer one is much smaller and doesn't have a spring. It just helps to keep sand and mud away from the real sealing area.

With this said, if the outer lip is not kept wet by oil or grease it usually wears a groove in the shaft that rotates within it.

Yes, that - or the lip just wears away. That's why at the time of installation one should fill the space between lips with some light grease. (Synthetic grease preferred.)

Is this seal really supposed to be double lipped or is the original design a single lip?

Original design is a fully encased single-lip with a built in felt ring facing to the outside. Those are not being made any longer so we just use modern double-lip seals, instead. And since these are narrower and there is plenty of room, one can run two of them in there, either stacked or back to back. (-> post #4)

 

[davidb56]

As Gringletaube said, if you can get two of the Timken seals in, the first one with the lip/spring on the oil side, and the second one with the lip/spring on the outside, this will prevent water from entering the pumpkin when it is submerged. I did that to a wagoner after numerous "drum puller" rentals and seal replacements when playing in the deep water decades ago.

 

[rustystud]

As Gringletaube said, if you can get two of the Timken seals in, the first one with the lip/spring on the oil side, and the second one with the lip/spring on the outside, this will prevent water from entering the pumpkin when it is submerged. I did that to a wagoner after numerous "drum puller" rentals and seal replacements when playing in the deep water decades ago.

The original military "double" seals haven't been used since the 1970's. At "Ben's Truck Parts" where I worked rebuilding old military differentials, transmissions', and transfer-cases they had a large supply of them. They where really wide and had two distinct lip seals. One facing in towards the oil and the other facing outward to prevent water and other crap from entering the unit. So since the differentials where designed for this wide seal, doubling the modern lip seals should work just fine.