i have a b33 1953/4 it has a 4 lobe cush drive .the engine was in bits when i got it ,im a bit stuck
rebuilding it with cush drive nut does it do up all the way ?.
if i do this the lobes will not have room to pass each other im wondering if it has a torque setting so is not fully done up or if i have a spacer missing or miss match of parts any idears
thanks paul
Paul, I've an M21 with an identical problem, so am equally looking for advice.
Everything I researched suggested the nut be done up tight; in fact it is the only way the lock washer can function.
Only last week I experimented by grinding some metal from the lobes on both parts. Although this worked, the cush drive now sometimes jumps a lobe when I attempt to kickstart.
Help for me and Paul please!!!!
There is actually a lock washer that fits on before the nut and if the spring is in good condition after tightening the nut up and replacing the split pin,, there is just enough room to get a punch in to nip it into a groove. HTH
Regards TTJohn
The cush nut needs to be tigtened right up against the sleeve, 60 - 65 ft/lbs torque suggested. Use some loctite on the thread dont just rely on the lock washer. If it comes undone you will wreck or at least damage the chaincase outer.
The cams on the cush ony give a few degrees of movement, just to take the shock out, they do not fully ride over.
The photos show the cush on my A10. The nut is an SRM one which allows the use of a socket.
First one shows nut fully up against the sleeve.
Second shows that the cams do not ride over each other.
Third shows the cams positions to account for the 24.5mm compressed length of the A10 spring. You can see the limited the movement allowed.
Same theory for the 4 lobe cush.
thanks every one i best go buy a locking washer