Front camshaft oil seal
1. Unclip the radiator fan shroud and position it on top of the fan blades as described in Chapter 3.
2. Where provided, remove the cover from the distributor cap. Disconnect the ignition coil high-voltage wires from the distributor cap. Then unscrew the three screws and remove the distributor cap. Move the cover aside together with the high-voltage wires and housing.
3. Unscrew the three screws and remove the distributor runner.
4. Loosen the mounting bolt and remove the runner drive bushing (see fig. 6.8). Where provided, unfasten the cover at the front of the upper camshaft drive chain housing.
5. Carefully pry up the old seal with a screwdriver. You can drill a hole in the seal and use a self-tapping screw and pliers to pry the seal out of its socket. Be careful not to damage the socket.
6. Thoroughly clean the oil seal seat and the front of the camshaft.
7. A piece of polyethylene or tape wrapped around the front end of the camshaft flange will help protect the new seal from damage during installation.
8. Using a pipe or suitable wrench head, carefully tap the new (dry) seal into the socket until it is flush with the outside surface of the chain case.
9. Where used, remove the plastic or tape from the camshaft.
10. Where provided, fit the cover to the front of the upper chain case, then fit the runner drive bushing, ensuring that the groove in the bushing matches the boss on the shaft. Fit the bushing retaining bolt and tighten to the specified torque.
11. Install the runner and tighten the mounting screws.
12. Install the distributor cap and connect the ignition coil high-voltage wire.
13. Install the radiator fan shroud.
Front crankshaft oil seal
14. Remove the crankshaft/vibration damper pulley and hub as described in paragraph 5.
15. Measure and record the cuff installation depth.
16. Pry and pull the seal out of the housing. Protect the crankshaft by wrapping the screwdriver in a rag (see fig.14.16). You can drill a small hole in the cuff, screw a self-tapping screw into it, and pull out the cuff using pliers.
Fig. 14.16. Removing the front crankshaft oil seal. A rag is used to protect the shaft
17. Clean the cuff body.
18. Dip the new seal in clean engine oil and press it into the housing using a pipe or a wrench (open end first) to the marked depth. A piece of thin polyethylene or adhesive tape wrapped around the crankshaft will help protect the seal from damage during installation.
Material borrowed from an online resource MercedesMAN
19. Where used, remove the plastic or adhesive tape from the crankshaft.
20. Install the crankshaft/damper pulley and hub as described in paragraph 5.
Rear crankshaft oil seal
21. Remove the flywheel/drive plate as described in paragraph 13.
22. Perform the actions described in paragraphs 15 and 16.
23. Check the crankshaft surface under the seal for damage. If significant wear is detected, the crankshaft should be replaced.
24. Clean the seal housing and the crankshaft flange surface.
25. Dip the new seal into clean engine oil and press it into the housing using a pipe or a wrench (open end first) to the marked depth. A piece of thin polyethylene or adhesive tape around the back of the crankshaft flange will help protect the seal from damage during installation. Note that for a reliable seal, the seal must be installed at a right angle to the crankshaft flange.
26. Remove plastic or adhesive tape from areas where it was used.
27. Install the flywheel/faceplate as described in paragraph 13.