Front Crankshaft Oil Seal
1. Remove the crankshaft pulley/vibration damper and hub.
2. Measure the installation depth of the sealing ring.
3. Using a screwdriver blade, remove the sealing ring from its socket.
4. Alternatively, drill two small holes in the O-ring, located at diametrically opposite ends of the O-ring. Screw two self-tapping screws into the drilled holes in the O-ring and, using pliers, pull the O-ring out by the screw heads.
5. Clean the sealing ring seat.
6. To protect the working edges of the sealing ring when installing it, wrap the end of the crankshaft with adhesive tape.
7. Dip the new O-ring into clean engine oil and, using a tubular drift of the appropriate diameter, install the O-ring into the seat to the previously measured depth.
8. Remove the adhesive tape from the end of the crankshaft.
9. Install the crankshaft pulley/vibration damper and hub.
Rear crankshaft seal ring
1. Remove the flywheel/drive plate.
2. Measure the installation depth of the sealing ring.
3. Using a screwdriver blade as a lever, remove the sealing ring from its socket.
4. Alternatively, drill two small holes in the sealing ring, located at diametrically opposite ends of the seal. Screw two self-tapping screws into the drilled holes in the sealing ring and, using pliers, pull the sealing ring out by the screw heads.
5. Check the condition of the crankshaft surface that contacts the sealing ring. If there is severe wear, the crankshaft must be replaced.
6. Clean the seal ring seat and the surface of the crankshaft that contacts the seal ring.
7. To protect the working edges of the sealing ring from damage during its installation, wrap the end of the crankshaft with adhesive tape.
8. Dip the new O-ring into clean engine oil and, using a tubular drift of the appropriate diameter, install the O-ring into the seat to the previously measured depth.
9. Remove the adhesive tape from the end of the crankshaft.
10. Install the flywheel/drive plate.
Original source of information MercedesMan