Gearbox removal

[KellyVB 75R90S]

Hi All,
Was wondering if it's possible to remove the gearbox without removing the rear tire? I remember way back when I did lube the splines and only disconnected the driveshaft.

Thanks
Kelly

[Airbear]

Kelly, the answer is 'no'. You need to detach the swing arm to make enough room.

I like to remove the whole drive train so I can properly check everything. For instance, with the shocks and final drive removed you can rotate the swing arm to check the state of the bearings before you remove them for cleaning and re-greasing. And so on. It takes me maybe 40 minutes to get to this stage:



Just a reminder - the very first thing to do (before removing the rear wheel) is pull back the driveshaft boot, plant your foot on the rear brake and undo the four bolts at the uni joint.

[Rob Frankham]

AS a matter of fact. it's perfectly possible on a twin shock model... wouldn't want to try it on a Mono...using a bit of latteral thinking.

• First put the bike on it's main stand on a level surface.
• Remove all those bits that have to come off (Seat, Tank, Battery & Holder, Air box & filter, Rear mudguard and carbs and anything else I haven't thought of). Disconnect the rear brake.
• Without disconnecting the rear shock absorbers, disconnect the drive flange and remove the swing arm pivots.
• Push the rear wheel backwards, still attached to the swing arm, as far as it will go and chock it back with a brick or something similar.This will allow the front of the swing arm to drop.
• You now have enough room to remove (and replace) the gearbox.
• Reassembly is (as they say) the reverse of disassembly. The only hard bit in my experience is relocating the front of the swing arm in the pivots as the position is awkward and the assembly is quite heavy.

That being said, I've only done this when I was in a real hurry and, even then, I'm not convinced that it saved an enormous amount of time or work. Unless there's a good reason why you don't want to remove the rear wheel, I would always advise that the job is done properly.

On the subject, to debunk a myth in most of the manuals, there is absolutely no need to move the engine or in any way disconnect the exhaust when removing the gearbox. There is ample room with the engine firmly bolted in place. The only thing you need to bear in mind is that you need to pull out the pushrod to make sure that it doesn't get caught as you remove the box (and don't forget to replace it before you bolt the box up again... You can't replace it when the box is fixed to the engine (DAMHIK ).

Rob

[KellyVB 75R90S]

Thanks Rob,
I was just wanting to be LAZY.
The last time I had the gearbox out (15 years ago), I sent it to Nathan at Boxerworks and he rebuilt it, I did remove everything as you did. This old gal is getting a main bearing change while I've got the gearbox out, new clutch, also going to take the heads off and sent to them to Teds Beemer shop for rework and maybe that the jugs and pistons off and also send them out for rework. She has NEVER had a valve job.
Thanks for the reply.

Kelly

[Seth]

It’s also a good time to lube the splines on the final drive to rear wheel.

[Zombie Master]

I always check My center stand bolts before doing any big job.

[richard t]

Thanks Rob,
I was just wanting to be LAZY.
The last time I had the gearbox out (15 years ago), I sent it to Nathan at Boxerworks and he rebuilt it, I did remove everything as you did. This old gal is getting a main bearing change while I've got the gearbox out, new clutch, also going to take the heads off and sent to them to Teds Beemer shop for rework and maybe that the jugs and pistons off and also send them out for rework. She has NEVER had a valve job.
Thanks for the reply.

Kelly

you got main bearing problems? It is good to hear from you