Finger tight + 1/4 turn with a 1/4" ratchet is fine, as long as the washer is installed. BTW, the manual says to install a new washer every time. Not necessary, as long as the washer isn't scored or deformed. I don't even bother with a torque wrench for any of the belt housing or rear drive housing bolts. Whatever you do, don't over tighten. It's too easy to strip an aluminum thread in the rear drive housing.