Hey 86560SEL ,yes it is a big damage so get yours done.And with your friend ,the diesel defenetly needs to be done soon to.As of the 300e that is what this whole forum is all about.Everyone is saying that they last 300+ k.Well i say as not someone that wants to sell you somthing,but out of experience to replcae the chain on the 300.You will probally get some guts after my answer come on and say,No dont worry the chain is good for ever.Well let them say it,but i have been repairing these cars long enough to know better.Hey the chain might last 250 - 300 k but would you risk it for a 3 grand bill when the chain does snap.The job should not cost more than 400 - 500 bucks.it is save insurance like i have already sayed that this will not happen