front primary sprocket seal

[Mark Jennings]

I have a 42 WLA and the seal behind the front engine primary sprocket is leaking and needs to be replaced. Is this a easy repair or do I need special tools to remove and replace this seal. The books I have are very vague on how to change this seal.
Also is there a torque spec on the nut that holds this sprocket on?
Thanks in advance for any help.

[T. Cotten]

I have a 42 WLA and the seal behind the front engine primary sprocket is leaking and needs to be replaced. Is this a easy repair or do I need special tools to remove and replace this seal. The books I have are very vague on how to change this seal.
Also is there a torque spec on the nut that holds this sprocket on?
Thanks in advance for any help.

Mark!

Your machine was not produced with a conventional seal, but a "slinger" instead. This is merely a bearing end thrust collar with reverse threads within its bore, to spin oil back into the motor.
It is often worn, and overlooked in rebuilds. Wear marks upon the shaft add to the clearance.

The slinger also acts as a safety valve to allow oil to escape upon sitting for extended periods, lest the cases completely fill with oil seeping past the checkvalves in the feed pump.
If your observed leakage follows such a period out of duty, you may wish to operate the machine for a while to see if the problem is really significant.

Removal requires that the external snap ring be removed, which can be quite tedious.
(A jeweler's torch can destroy the ring's temper, making it much easier.)
Removal of the bearing end can be equally a test of patience, (sticking a small welding rod to it for pulling is an option), and the replacement must fit the race bore precisely.

Naturally, this is all easier with a disassembled left case on the bench.

A modern alternative is Colony's bearing end with a modern seal installed.
But again, the race bore fit can become an issue, wear marks upon the shaft may limit its life, and there will be no escape valve for sumping.

I must defer to others for a torque spec,
Good luck!

....Cotten