1980 Ski-Doo Shop Manual, Page 282Get this manual
SECTION 05 SUB-SECTION 08, (GEARBOX)
NOTE: It is necessary to cut hole in fiberglass
frame in order to be able to reach chain tensioner retaining bolts and nuts
Install assembled drive shaft into lower housing then using feeler gaugecheck total free-play between components installed on the drive shaft side of sprocket Free-play must not exceed 0.15-0.30 mm (.006 to .012")If free-play is not within toleranceshim to
correct tolerance
)Layshaft gear free-play:
retaining bolt
Remove gearbox, chain and !ower sprocket from vehicle
INSPECTION
Check general condition of chain linkageVisually inspect drive chain for crackeddamaged or missing link rollersInspect security of riveted heads of link pinsVisually inspect oil seals for cuts or damageInspect sprockets and gears for damageworn teethor spline distortionInspect general condition of bearings (pitted or missing roller bearingsfreedom of movement and radial freeplay)Inspect drive shaft for deflectionworn or twisted splinesPlace the assembled lay gear into the lower housingUsing feeler gaugecheck end play between assembled layshaft and walls of lower housingEnd play must be between 0.15-0.30 mm (.006 and .012")If end play