2009 Yamaha F40 Outboard Service Manual, Page 274Get this manual
Shimming 6Place the pinion facing upward and hold it in the upright position7Rotate the drive shaft 10 turns or more to seat the taper roller bearing8Tighten the pinion height gauge bolts in stages to the specified torque so that the distance between the upper part and the lower part of the special service tools become equal10Measure the gap between the pinion and the special service tool aWhen measuring the gap, insert the end of the thickness gauge straight into the gap at the measurement pointDo not insert the thickness gauge at an angle 0 1