2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 183Get this manual
CRANKCASEITRANSMISSIONCRANKSHAFT Install the cam chain guide sprocket and guide spindleHold the guide sprocket and tighten the guide spindle
RIGHT CRANKCASE Drive the mainshaft and countershaft bearing out of the right crankcase
Apply engine oil to the new mainshaft and new countershaft bearingsDrive the new mainshaft and countershaft bearings into the right crankcase using the special toolsTOOLS: Mainshaft bearing: Driver Attachment, 37 40 mm Pilot, 17 mm Countershaft bearing: Driver Attachment, 32 35 mm Pilot, 12 mm