Replacement
1. Remove the gearbox.
2. Remove flywheel.
3. The stuffing box can be removed with a special tool or a screwdriver, but it is safest if you remove the stuffing box casing and knock the stuffing box out of the casing.
4. Install a new oil seal in the casing.
5. Install a new casing gasket, install the casing to the cylinder block and tighten the bolts.