Several case modifications must be made before the 6-Speed can be installed. The first is the sixth gear clearance. This is done by using the side door gasket as a template. All material above the gasket line at the screw hole pictured (Photo 11) must be removed.

Photo 11

Photo 12

Next is the clearance for the auxiliary fork shaft bridge. This is done with the same procedure, using the gasket as a guide (Photo 12).

The right side pillow block and roller detent clearance must also be checked in the areas shown (Photos 13 & 14). 
 

Photo 15

Now is also a good time to check the shifting drum end clearance (Photo 15), and the shifter pawl adjustment.

The case must now be cleaned thoroughly.