Quote: you want BOTH joints to be in line while under load...
.... then rotate the pinion down which will give BOTH joints movement for lube while not under full load
if you have everything inline with no misalignment the ujoints do not move, just spin with the crank/driveshaft/pinion leaving the needle bearings stationary. That creates point contact between the roller and shaft causing flat spots under load. For the needle bearings to roll you need working angles and the front and rear should cancel each other out to maintain constant velocity. IMO you want a small equal but opposite working angle under load to work the ujoints. when the working angles are to far off is when you have driveline vibrations due to the different velocities in the ujoints. flame away.
