2006-2014 Honda FourTrax ATV TRX250 EX TRX250X Service Manual, Page 208Get this manual
CRANKCASETRANSMISSIONCRANKSHAFT Check the transmission gears for freedom of movement and rotation on the shaftApply engine oil to the gear teeth and shaft journalsEngage the mainshaft and countershaft gears: Gear teeth and shaft journ als COUNTERSHAFT
MAINSHAFT Position the crank weights so that they do not interfere with the mainshaftTake care not to drop the thrust washer on the mainshaft
Install the mainshaft and countershaft as an assembly into the rear crankcase, being careful not to damage the countershaft oil seal