2000-2005 Yamaha F40B Outboard Service Manual, Page 320Get this manual
SHIMMING (FOR USA AND CANADA)
(2) Install the shimming gauge, drive shaft, drive shaft bearing CD, and pinion shim(s) CV
Gauge block YB-34432-8 Adaptor plate YB-34432-10 Gauge base YB-34432-11 Clamp YB-34432-17
If the original shim(s) is unavailable, start with 0.50 mm shim(3) Install the pinion and pinion nut