1970-1979 Ski-Doo Snowmobiles Service Manual, Page 137Get this manual
CHAPTER SEVEN
8Remove nuts and washers from "U" clamp securing chaincase to frame (Figure 28)9Note number of shims, if any, between chaincase and frame and remove shims10Shift chaincase and disengage hinge rod11Remove drive axle12Using large screwdrivers between chaincase and frame, pry chaincase assembly from machine