AMC Gearbox seal

[Plugsnpoints]

I have the gearbox sitting on the bench so thought it'd be a good idea to replace the seal behind the sprocket.

Have any of you got any tips on making it easier when undertaking this work please?

I have changed the seals on the outer case already. Is there anything else I could do to give it a treat? Is there any other seals that will benefit from replacement? Obviously I shall refill it with fresh oil after installing it on the motorbike. It works perfectly after 62 years so it's doing well.

Thanks ladies and gents.


Andy

[matchless]

Don't forget the sprocket nut is a left Hand thread.
have you checked the 2 x o-rings on the side of the main case. These are for the selector cam plate and arm.
Check an exploded diagram for details.

Regards...........David

[Plugsnpoints]

Don't forget the sprocket nut is a left Hand thread.
have you checked the 2 x o-rings on the side of the main case. These are for the selector cam plate and arm.
Check an exploded diagram for details.

Regards...........David

Thanks David,

I didn't realise the sprocket nut is left hand thread. I'll look at the drawing regarding the O rings. I have a complete gasket kit.

Andy

[Plugsnpoints]

My next question is-what size is the gearbox sprocket nut? I have a box spanner that fits but think a ring spanner might be better.


I also need to find a bit of old chain to lock it off as I've long thrown mine away-the joys of owning a shaft drive bike.

Thank you.

Andy

[Mick D]

I have a box spanner that fits but think a ring spanner might be better.

Hi

The sprocket nut is rather thin and as such the chamfer on a ring spanner reduces the contact area even more - best option is to grind the chamfer off of a suitable socket, but for occasional use I'd opt for a box spanner every time.

Regards Mick

[Pharisee]

I've turned the chamfer off the end of a socket and use it with an air impact driver if I've already removed the mainshaft. Otherwise it's a tube/box spanner.
John

[Plugsnpoints]

Thanks for the replies, they're very helpful.

Can anyone confirm what spanner/socket size it is please?

[PGGuse]

My solution as to the pic: spanner size is metric 38 mm
Paul

[Plugsnpoints]

My solution as to the pic: spanner size is metric 38 mm
Paul

That is very helpful as it answers two questions! I didn't understand why the pipes weren't connected between the crank and the oil tank! The one from the main was just pointed downwards into thin air, and so was the tank one.

Thank you for that. (I wondered why it left more than normal puddles of oil!) It's an easy fix while it's apart.

This club gets better


Andy

[SPRIDDLER]

I'm not certain but from the Spares List I think the standard touring bikes had just the short breather (Release) pipe 000755 pointing down behind the chaincase. Comp models had the extension pipes 018742 and 018743 returning oil mist to the tank.

Vent pipe for breather (640x127).jpg

Vent pipe breather 2 (600x433).jpg