Yamaha F100B F100C Outboards Factory Service Manual, Page 165Get this manual
Drive shaft and lower case (F100B) Disassembling the lower case
1Remove the taper roller bearing outer race and shim(s)
Checking the pinion and forward gear
1Check the teeth of the pinion, and the teeth and dogs of the forward gear for cracks or wearReplace if necessary
NOTE: Install the claws as shown
S60C6220
Checking the bearings
Bearing outer race puller 1: 90890-06523 Outer race puller claw 2: 90890-06532 2Remove the needle bearing1Check the bearings for pitting or rumblingReplace if necessary