As the title states, I need to replace the water pump on a 420SEL. I've worked extensively on most cars but never a Mercedes. My computer says it takes 6.7 hours. My question is this, are there any special tools I should need or special tricks with the timing chain? I haven't even seen this car yet but found out that it's tied in with the timing chain. Is this true? Does it really take 6.7 hours? I saw in a few posts that the distributor needs to be removed and the dampener turned to tdc. I'll continue to search the forum and if I find an answer before I get a response here I'll let you guys know. Or if you know of another topic with this question already posted just give me the link. Thanks for your time, Josh.