Questions and Answers

Mercedes 300SD Timing Chain Q. Can you send the diagrams on how to replace the timing chain and all the pulleys on a 1985 Mercedes Benz 300SD turbo diesel? If you can, send them ASAP.

A. If you are replacing the timing chain, oil pump chain, chain guides and gears, there are a few special tools you're going to need. In addition the crankshaft gears have to be heat pressed on. My recommendation, have it done by a Mercedes Benz Dealer or someone who has the proper tools to do the job.

If it is a model 126.120, the engine has to come out of the car. If all it needs is a timing chain, then a dealer can replace just the chain in about three hours.

• 28 Crankshaft sprocket
• 53 Camshaft sprocket
• 85 Tension rail
• 89 Slide rail
• 93 Outer slide rail
• 93a Inner slide rail
• 94 Chain retainer
• 98 Injection timing device
• 98a Idler
• a Chain tensioner

After you do this you'll see why they say "Engineered like no other car in the world".