2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 256Get this manual
REAR AXLEFINAL DRIVE GEAR AND DRIVE SHAFT
Ring gear stopper clearance adjustment 1.Remove: Ring gear Ring gear stopper Shim(s) 3
4 Bearing housing Left-hand threads
2.Select: Suitable shim(s) Shim Thickness (mm) 0.10 0.30 0.15 0.40 0.20 0.50
3.Install: Shim(s) Ring gear stopper (left-hand threads)
9 Nm (0.9 kg, 6.5 ft lb)