When I did mine a couple of years ago I didn't want to take a chance with such a vital part. So I went to the dealer got the chain, guides, and tensioner. Sure I probably paid an extra $100, but if the chain lets go it will cost me at leat $5k to replace the engine.

I also got the proper MB crimper from the tool rental program here.


Don't take chances with the timing chain, this is not the place to save money.


I'm more familer with 603's. On them with good oil changes you will see about 1 degree of stretch every 100k miles. 603's are more picky than 617's with timing, they really need to be dead on +/- 1 degree at most. 617's will be happy 3-4 degrees off, I bet 95% of the people on this forum wouldn't notice the difference. So on a 603 say around 250kish check it, see what you have and change if you need to.

Of course you never have to change it, if you are willing to accept slightly less then perfect preformance you can run the original chain to well over 400k miles; many people do.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200