Inspection and restoration of distribution mechanism parts (Mercedes-Benz E-Class W123)

1. Check the camshaft journals for scoring and measure them with a micrometer in several places to determine taper or ovality.

2. Inspect the bearing surfaces in the posts and housings to see if there are any signs of wear in the form of grooves or burrs.

3. Where the above defects were found, replace the camshaft and its struts or housing.

4. Replace the camshaft if the cam lobes are excessively worn, replacing the cam followers at the same time.

5. Inspect the camshaft sprocket(s), crankshaft sprocket, intermediate shaft and its sprocket, timing gear and oil pump drive gears and replace them if excessively worn.

6. Wash the camshaft chain with kerosene and check it for wear. Place supports under both ends of the chain so that the rollers are vertical. A worn chain will sag significantly, while an unworn chain will only bend slightly in the middle.

7. Check the tensioner and chain guide for wear and replace if necessary.

8. Check that the inlet holes of the camshaft oil pipes are not clogged, and on the M 110 engine, check the distributor drive pinions for wear.

Information copied from the website: MercedesMAN