oil leak from the top of series III gearbox

[dixe]

I have an oil leak from the top of my gearbox. I have checked the service manuals and they do not tell me about changing any oil seals. I think that is leaking from the gear lever shaft. Does anybody know the part number of the oil seal and how to change it.

Dixe

[bill van snorkle]

Leaking from the top is what all series gearboxes do. The selector shafts protrude through the front of the gearbox top lid and have square section O rings fitted to seal them with the housing. Whenever the exposed selector shafts get coated with mud or dust and you change gears, the O rings and the selector shaft bores in the alloy housing wear a little, sometimes to the stage that new O rings won't cure the leaks, especially if the vehicle is used in sandy/salty environs. Replacing the O rings involve first removing the gearbox top lidi ncluding detent springs/balls and interlock pills, then removing and disassembling the selector forks from the selector shafts. It would pay to reference a workshop manual if you want to do this job correctly.

The gear lever itself does not enter the gearbox, so the leak won't be coming from that.

Bill.

[Lars L]

To add to what Bill is writing, the O-rings aren't exactly square. They are in fact a bit wedged on the inside, so installing them the right way around is of importance to get them to seal properly. Even the lid itself can leak as there is no gasket. A little gasket goo on the surfaces can make a difference.

[dixe]

I have changed those oil seals but the oil leak is coming from the springs which hold the ball bearings in place. Does any body have any ideas on how I could seal them. I was thinking a dab of silicon at the end where they are held in place.

Dixe

[Les Henson]

I normally pluge the detent ball and spring in grease before fitting them - this should stop oil from coming out.

Les.