Rear Drive
I needed to change the oil seal because it was leaking and I imagine had been leaking for some time. There is a little vent hole in the rear drive housing that directs the oil away from the breaking area incase the oil seal does fail. In my drive this hole was nearly completely blocked hence my reasons for suspecting that it had been leaking for some time. This is the rear drive housing before cleaning. The crown wheel, pinion and the main seal removed.
This is the crown wheel and pinion. One of the shims for the main bearing is sitting on the workbench. I was fortunate in that all the bearings seamed to be OK so there was no need to press them off and replace. It made life a whole lot easier since if none of the bearings need replacing and the back lash measures OK then no new shimming is required. Re shimming the rear drive is an art in itself and the Grey beards tell me that it isn't easy to get right.
These are all the components for the rear drive after cleaning. I washed everything out with a strong solvent and cleaned the drive case with scotch brite WD40 and kerosene.
After replacing the seal the housing must be heated so that the crown wheel can be replaced. Make sure you don't forget to put the shims back in before the crown wheel......as I did. I had to pull the crown wheel back out again.
This is the pinion replaced. The case needs to be heated again. There are also shims so don't lose them or forget to replace them. There is also a seal in the threaded bell housing support. I guess it's a good idea to replace this seal while you're at it. You can see it, it's that black ring around the pinion
Top back on and all should be well. When you tighten the nuts down, do so in a diagonal pattern such as you would do with the cylinder head. It just helps to distribute the force evenly.
And this is what all the effort was for. You can see the new blue seal around the drive and the old black one on the bench.