Hi all,

I am replacing seals and bearings in my Jumbo engine and have a few questions:

- does the gear box internals stay in the clutch side or front sprocket side of motor when split?

- is heat needed on the main bearings to come away from the case?

Thanks in advance,,

Your best bet is to contact Martin, who will know the answer and can sort your spares for almost anything SWM

www.motoswm.com

 Stays in the clutch side. Years ago I made a (thin) steel plate that I attached a puller too. The plate would fit just over the crankshaft (after the flywheel was removed) and the holes would line up with the mag cover bolts.( I used longer bolts) It took 30 or so minutes to make, but it still sits in my tool box today.  Made the whole job much easier. 

Edited January 23, 201610 yr by lineaway

Wrong....gearbox stays on the sprocket side. Or more commonly falls out all over the place when you split the motor, but has to rebuilt on the right hand (sprocket side) crank case.

 

Tap the casings apart with a hide mallet/rubber mallet etc, you don't need heat to split them.

 

Also remember that the crank seals have to be pushed inwards (towards the crank) to remove them as the casings have a lip on the outside of the seal.

 

Martin

 No Martin, I had it right then changed my mind. Thanks for setting me straight!

Do crankcase seals go from inside on the smaller motors as well ?

Crank seals on the disc valve motors can be installed from either side, theres no retaining lip cast into the case or valve cover.

Thanks all!

I have done lots of Bultaco's but first SWM.