2002 Yamaha YFM660 Grizzly factory service and repair manual, Page 235Get this manual
MIDDLE GEAR
Where:numeral (usually decimal number) on the bearing housing is either added to or subtracted from "7.5"b17.055.0numeral (usually decimal number) on the right crankcase specifies thickness of "64.98"
Example: 1) If the bearing housing is marked "+02", is 7.52, 2) is 17 3) is 55 4)If the crankcase (right) is marked "64.98", is 64.985) Therefore, the shim thickness is 0.50 mmA7.5264.98 17 550.50 6) Round off hundredths digit and select appropriate shim(s)In the example above, the calculated shim thickness is 0.50 mmThe chart instructs you, however, to round off to 0Hundredths 0, 1, 3, 4, 5, 6, 8, Round value 10