by colm54 » Thu Nov 20, 2008 12:30 am
Can you be more specific about where the oil was? The alternator cover covers basically two compartments. The one on the right is the alternator and the one on the left is the engine sprocket. If there is oil leaking from the one behind the alternator, that would be from the main seal. If there is a significant amount of oil in the chain area, it could come from the sprocket oil seal, neutral switch or even from the grease on the chain. Or perhaps the chain was oiled rather than greased. Loosen the engine nut first after knocking off the tab washer, then you loosen the chain to give you wiggle room, remove the split link then let the chain hang down. I would recommend locking the rear wheel so it cannot be turned by accident after loosening the sprocket nut. If you should roll it off it's stand by accident it will smash the rear chaincase.
Once the sprocket is removed there is a cover retained by counter sunk screws, they may be covered by grease so wipe this away carefully, the cover plate will have a gasket and perhaps some shims underneath it. It's easy enough to push the seal out by immersing the plate in very hot water and the pushing out the seal, you can fit a new one just as easily. Please remember to refit the shims and gasket. The gasket packing is important, please reuse it. If not you will have to readjust the gear spacing by removing the correct shim.
After you have reassembled everything pack in some fresh grease around the sprocket and chain.
It is important to note that the chain is run a little loose. The chain gaitors makes it a little difficult to adjust but if it is adjusted too tight you can easily destroy the gearbox, chaincase etc.