1971-1973 Arctic Cat Snowmobiles Factory Service Manual, Page 122Get this manual
TRANSMISSION (STLAWRENCE) Inspection
1Inspect the drive plate, the synchronizer, and the safety plate and spider assembly for imperfections in the castingInspect the safety plate and spider assembly for fatigue cracks, distortion, and elongationsInspect the nylon bushing for any visible wearReplace as necessaryInspect the spring for fatigue or damageReplace as necessaryInspect all threaded parts for stripped threads or otherwise damaged threadsReplace damaged componentsCheck the idler bearing and spring collarif damaged or if condition is doubtfulReplace