Diesel Timing Chain
 

My '85 300SD just had vacumn pump failure. At 276K, this is not a surprise. Question, should I replace the timing chain while I am at it?
There seems to be no recommendation on time or miles to do the chain and it "looks" O.K.
thanks
martin

Looks can be deceiving
 

Search around Diesel Discussion for the stuff on checking the cam timing with a dial indicator -- the amount of retard is the most reliable indication of dangerous "stretch" (wear in the pins in the chain links). But do check to make sure that no one has already compensated for some of the chain wear with an offset Woodruff key.