1980 Ski-Doo Shop Manual, Page 270Get this manual
SECTION 05 SUB-SECTION 07 (CHAINCASE)
REMOVAL
Remove pulley guard, drive belt and inspection coverRelease chain tensionRelease track tensionPry oil seal from chaincase (lower part) and drain oilDisconnect brake cablePry out lower access plugRemove cotter pin and spacerRemove nut on hinge rod at chaincase bracketFrom the inner side of frame, remove the nut securing chaincase lower bracketRemove bracketRemove nuts, washers and "U" clamp holding the chaincase to the frameRemove chaincase shim(s) if applicableMove chaincase towards drive pulley to disengage hinge rodRemove drive axleUsing two (2) large screwdrivers inserted between chaincase and frame, pry complete assembly from vehicle
Bearing cup
Oil retainer ring
Convexe Side
toward all sea!
Using an appropriate pusher, press oil seal mto chaincase hubOil seal must sit flush with case hub edgePlace lower sprocket with longer flange toward track side of chaincase(For proper sprocket and chain use, see Technical Data
INSTALLATION
Longer flange