My 560SL will reach 100k miles about late Spring and although the engine is smooth and quiet I will do the chain-tensioners-guides-oilers job at that time.

In regard to sprockets, I would inspect those closely for hooking. If any sign they should also be changed. My major sproket experience is with Shovelhead Harleys and they usually required a sprocket change with every other rear chain change. A hooked sprocket will shorten the life of a new chain drastically. The Benz cam chain runs in a sealed environment (as does the dual row primary chain on the Hog) and is well lubricated hence the approximately 100k mile lifetime.

100k miles is pretty good for a complex mechanical assembly that has a hard life like an automotive roller chain. One factor in chain life is sprocket diameter; the smaller the radius, the shorter the chain life. One can assume the Benz engineers designed the optimum configuration.

The summary of all this boushwa is: If your sprocet shows wear by "hooking" or "pointing" change it. If you don't your chain life will be even shorter next time.

If you guys already knew all this, just call me Captain Obvious.