FC Diff Pinion Seal

[fc25250]

Got a bit of a leak not major but thought should be an easy fix !
Just wondered what Rarespares mean by pinion seal for “early” FC
Are there different seals available for the FC ? I.e early and later models on the Fc range ?
Don’t want to get one and then find it won’t fit.

Thanks for any help from member who have replaced theirs.

[ardiesse]

The replacement diff pinion oil seal is a flimsy imitation of the original, and is very easy to distort when installing.  The original has a leather inner seal, and a felt outer.  The replacement is a spring-loaded rubber lip seal.  You'll probably find that your pinion flange is grooved, making it very difficult for the replacement seal to seal up.

All Holden diff pinion oil seals leak.  The shop manual says, "An occasional drop of oil is to be considered normal and does not warrant attention."

The newer-style 3.89 diff centre was introduced part-way through FJ production.  At about FE time, the pinion oil seal was revised to the leather-plus-felt type.

Rob

[fc25250]

Hi Rob
My diff housing is not overly oily so I will let it be.
Thanks your comments
I have noted a vast variation of prices for this seal so can I assume that the difference is for the reasons you state ?
Paul

[Dr_Terry]

All Holden diff pinion oil seals leak.  The shop manual says, "An occasional drop of oil is to be considered normal and does not warrant attention."
Rob

One of my pet hates is unnecessary oil leaks. Seal technology in the 1950s was very basic, but has improved markedly from the 1980s onwards.

I always try & source Viton type seals, which is a much tougher material than even the more commonplace modern Nitrile.

Another source of diff leaks is up thru the pinion spline. If you smear some sealant on the spline on assembly, & use a Viton pinion seal, the diff will be dry.

Dr Terry

[Jolls]

Dr Terry,

I'm a little confused. Doesn't the pinion seal run on the finished pinion surface prior to the spline? If so the leak is prior to the spline and would be flung off due to gravity.

When you say smear some sealant on the spline what type of sealant do you mean?

Cheers

[Dr_Terry]

Dr Terry,

I'm a little confused. Doesn't the pinion seal run on the finished pinion surface prior to the spline? If so the leak is prior to the spline and would be flung off due to gravity.

When you say smear some sealant on the spline what type of sealant do you mean?

Cheers

The oil has only 2 ways to exit the diff pinion. One is past the seal & the other is up thru the spline. If you look at a cross-sectional pic of the diff you will see what I mean.

My sealant of choice is Permatex Grey. It's a good sealant for oil or coolant & is far better than Silastic etc.

Dr Terry

[Errol62]

Same problem can occur between the crankshaft snout and harmonic balancer, where oil leaks out through the keyway.


Sent from my iPad using Tapatalk

[Jolls]

The oil has only 2 ways to exit the diff pinion. One is past the seal & the other is up thru the spline. If you look at a cross-sectional pic of the diff you will see what I mean.
My sealant of choice is Permatex Grey. It's a good sealant for oil or coolant & is far better than Silastic etc.

Dr Terry

I get it now - thanks for clarifying.

[Jolls]

Same problem can occur between the crankshaft snout and harmonic balancer, where oil leaks out through the keyway.


Sent from my iPad using Tapatalk

Thanks for the heads up