Gearbox output Bearing

[bsarider]

Dear All,
         On tensioning my rear chain I find that my primary chain seems to have also tensioned itself slightly I suspect there is a bit too much wear in the gearbox output bearing,is it a big job to change the bearing? do I need to remove the gearbox? and can I leave the engine in situ? all these questions are sent to test us.Thanks for all your replys.

[Rocket Racer]

Havent done this bearing on a semi unit, but that bearing does push in from the clutch side, so if you stripped the gearbox internals out and the bearing circlip and took the clutch and primary, arguably you could do it in situ although I suspect it would be a lot more fiddly.
I have a later pre unit gearbox apart at the moment and nice and easy to work on it out of the bike.

Whatever you do its no small task, may pay to bite the bullet and drop the motor and box so you can unbolt the box.
Could well be wear in the bushes in between the sleeve gear and the mainshaft.

Probably time to inspect the box properly.

might pay to have a wrestle with the clutch first and see if the play in the box is really that bad before you get too carried away.

[Brian]

You do have to remove the gearbox to replace this bearing and on the rigid/plunger models its easier to take the whole engine/gearbox unit out.

If this bearing is worn then its most likely time for a full gearbox rebuild.

[A10Boy]

On swinging arm model, is it a definite that the bearing can't be changed without taking the gearbox out??

[chaterlea25]

HI A10Boy,
It is possible to change the output bearing without removiing the main casing on the swing arm "A"
But at that stage of dismantling another 5 or 10 min will have the case out which makes it easier to work on!!
If you had the special "SKF" bearing puller set which hook into the groove in the bearing it may be possible to remove the bearing from the outside without dismantling the box??
BUT, in my experience if the outer bearing is worn so will all the other bits inside the box!!!!
HTH
John O R

[A10Boy]

Thank for the reply, I will take the box out.