Replacement
1. A common cause of leaks in the gearbox housing is wear of the rear seal in the housing tailpiece and bushing (if provided), as well as the oil seal and the sealing ring of the speedometer gearbox. These parts can be replaced without removing the gearbox.
2. Raise the vehicle. A leaking seal is visible by oily deposits on the front of the driveshaft and on the end of the gearbox tailpiece.
3. Remove the driveshaft (see subsection 7.3.2).
4. Carefully dislodge the mud deflector using light blows from a soft-faced hammer.
5. Pry up and carefully remove the seal.
6. If the seal cannot be removed, it should be removed using a special tool (available for sale).
7. Press in the new seal using a mandrel, making sure that the seal fits in without being skewed.
8. Press on the mudguard.
9. Lubricate the splines of the fork and shaft and install the driveshaft, being careful not to damage the edges of the new seal.