Originally Posted by FreeTheBeast
So is shimming the driveshaft not required? I thought I read somewhere that some shimming was required when raising the motor.
You want to keep the u-joint of the driveshaft in the same spot vertically that it was before. The driveshaft is free to move up and down on the front end, but at the back the splines in the final drive are fixed. If you move the driveshaft forward or backward, up or down, you're changing the axis of the driveshaft in relation to the rotating axis of the final drive input spline. The only way these two can remain coaxial throughout the suspension travel is if the u-joint at the front of the driveshaft is directly inline with the pivoting axis of the swingarm. Not watching out for that will result in undue wear on your final drive input and drive shaft splines. Since the whole mess is drenched in gear oil, the wear probably wouldn't be that rapid though.