2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 255Get this manual
REAR AXLEFINAL DRIVE GEAR AND DRIVE SHAFT Remove
the ring gear assemblyMeasure the thrust clearanceCalculate the width of the flattened Plastigauge 1Ring gear thrust clearance: 0.10.2 mm (0.0040.008 in)
out of specification, select the correct washer
Thrust washer selection steps: Select suitable thrust washer using the following chartThrust washer 1.2 1.5 1.8 2.1 1.3 1.6 1.9 1.4 1.7 2.0