2005 Ski-Doo Racing Handbook, Page 417Get this manual
SECTION 102004 MX 440
Drive Sprocket Replacement
Procedure
Validate that vehicle is equipped with suspect drive sprockets (black)Remove rear shock absorber to prevent damaging shock absorber rodRemove rear suspensionRemove speed sensor and outer flangeApply parking brakeDrain chain case oil, remove chain case cover and release drive chain tensionNLower gear bolts are secured with Loctite, heat may be required to remove the bolts; be careful not to overheat, this would damage seal bearingRemove chain and sprockets from chain caseRemove lower bearing retaining C-clipRelease drive axle sprocket from track and, at the same time, push drive axle toward right sideRemove lower bearing from drive shaft and remove shaftNTo remove press-fitted sprocket, use press and suitable supportRemove speed sensor adapterRemove C-clip and bearing from shaft, discard bearing and protectorPress both sprockets to the inside to allow free movement of the retainer ring and remove C-clipNSprocket needs to be pushed in and out of the shaft by the left side (speed sensor side)NTo assemble press-fitted sprocket use press, suitable pipe and supportPress-in sprockets to allow enough space to install retainer ring and clip; remove plastic burr to allow retainer ring to sit correctly against sprocketNSprockets need to be positioned with rounded side1] OUT; refer to illustration below] CAUTION: Ensure to align index marks of each sprocket when assembling