Final drive seal replacement - removing stuck seal

David Morrow · Aug 28, 2016

I thought that I would start a new topic as I've pretty much determined that I have at least one bad seal in my final drive assembly and not at the engine end of things. It's the one at the back end of the drive shaft. ( I also bought the seal for the coupler that sits further inside. )

The shaft absolutely refused to disengage from the FD unit and, since the seal looked pretty well gone in places, I just cut into the seal and the shaft finally popped right out.

The problem that I now face is removing the remnants of the old seal from the shaft. You can see the remains in this picture. There is what appears to be a copper ring down below the rubber. I have cut away some of the rubber and have nicked the metal in a place or two. I'm am really afraid that if I badly mar the shaft mating surface, the new seal will leak. I'm not sure if the copper that you see is a metal ring built into the seal for rigidity and strength or if it is permanently affixed to the shaft and is the mating surface for the seal.

Can anyone provide any guidance on removing the old seal and what that bit of copper coloured metal is ?

audiowize · Aug 28, 2016

Put a heat gun on it, soften it, then break it apart with a wood stick (or your chopsticks from lunch).

David Morrow · Aug 28, 2016

Maybe it's odd to reply to your own topic but here's what I did in case anyone else has this problem :

I attacked it with a heat gun and spray on gasket remover. Heat didn't work, or maybe I didn't have enough patience. The gasket remover and a razor blade did. I got most of the rubber off. In the process, that brass colour scraped off. At least the brass colour gave me a clue that this bit of metal was not part of the shaft though.

Next, I put a digital caliper to the I.D. of the seal - it's about 23 mm. The O.D. of the formerly brass ring is about 26 mm. So, it's not the mating surface. And, as the gasket remover did its job, the rubber came away from the forward edge of the brassy ring and I could get a very sharp dental pick under the ring and got more rubber.

So, the conclusion is that the ring is part of the seal. Mystery solved. Now it just need to get it off but that will come with a bit of time and effort at the bench.

Thanks all for listening.

David Morrow · Aug 28, 2016

The Dremel cutoff wheels was the trick. I knew there was a layer of rubber between the ring and the shaft's seal mating surface so I had a bit of leeway when I cut into it. Took all of about 30 seconds.