2001-2005 Honda TRX250EX Sportrax TRX250EX Factory Service Manual, Page 246Get this manual
REAR DRIVING MECHANISM Remove the oil cap and set horizontal type dial indi ca tor on the ring gear through the filler holeTurn the ring gear back and forth to read backlash STANDARD: 0.05-0.25 mm (0.002-0.010 inl SERVICE LIMIT: 0.4 mm (0.16 inl Remove the dial indicator, Turn the ring gear 1200 and measure backlashRepeat this procedure once moreCompare the difference of the three measurementsSERVICE LIMIT: 0.2 mm (0.080 inl If the difference in measurements exceeds the service limit, it indicates that the bearing is not installed
squarely, or the case is deformedInspect the bearings and case
If the backlash is too small, replace the ring gear left
side spacer with thicker oneBacklash is changed by about 0.06 mm (0.002 in) when thickness of the spacer is changed by 0.12 mm (0.005 in)NOTE: Eleven shims (from to KJ are available in thickness increments of 0.06 mm (0.002 in)Right ring gear shims: A: (thinnest): 1.26 mm (0.050 in E: (standard): 1.56 mm (0.061 in)K: (thickest): 1.86 mm (0.073 in )