No experience at doing one but to get at a seal in there you would have to open the gearbox. That would require:
Seperate the housing from the tractor.
Remove the side rake support shaft bearing.
Remove the intake side cover.
Remove the back pulley.
Pull out the shearping and remove the rakes.
You not have access gearbox and can open it starting by pulling out the auger drive shaft.
This is rough description from the online manual. Search the forum for pointers to the manuals, owners and serivce. I think there are three seals in there, to the right and left of the helical gear and one in back of the worm towards the engine.
The chances are high it will outlive you. If you maintain these things and use it properly they just keep going.
trouts2
