2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 145Get this manual
Shimming
Shimming
NOTE: Shimming is not required when assembling the original lower case and inner parts Shimming is required when assembling the original inner parts and new lower case Shimming is required when replacing the inner part(s)
NOTE: Tighten the clamp bolts another 14 of turn after they contact the clamp 24Install the pinion and pinion nut, and then tighten the nut to the specified torque
Selecting the pinion shims
1Calculate the specified value (M0) as shown in the examples below