1974 Ski-Doo Shop Manual, Page 48Get this manual
REMOVAL Remove pulley guard and drive belt Release track tension Pry oil seal from chaincaseUnbolt brake assemblyRemove chaincase cover and drain oilRelease chain tension then remove cotter pin locking lower sprocketRemove spacerRemove bolts securing chaincase to frameRemove aligning shim(s) then using two (2) large screwdrivers inserted between chaincase and frame, pry complete assembly from vehicle
Using an appropriate pusher, press oil seal into chaincase hubOil seal must fit flush with case hub edge Position
lower sprocket with longer f.lange facing in side of case(For proper sprocket and chain use, see echnical Data)
INSTALLATION
Prior to installation, ensure that the spacerhas remained on drive axle and also, that chaincase frame spaceris in positionPosition assembled chaincaseInstall spacerand new cotter pinto secure lower sprocket to axle Proceed with pulley alignment Secure chaincase to frame Install chaincase flange oil sealA gap of approximately 116" should exist between the end of chaincase flange and oil seal16"