Timing Chain & Guide Replacement
 

My '87 560SEL is nearing 100K on the engine (215K on the body) so I'm starting to think about chain, guide, and tensioner replacement. I've reviewed posts here, on mbnz.org, and mbz.org and all seem to indicate that this is a possible DIY job that simply requires some time and lots of patience. I've rebuild a couple of non-MB engines in my day so I'm no stranger to the inside of a V8 but have never dealt with an overhead cam engine. I like the idea of replacing the chain with only one valve cover removed rather than having to pull the entire front of the engine apart ;-)

However, I do have one question - where are the various chain guides that seem to be the most important part of this repair and can they too be replaced without removing all the front accessories and the timing cover?

Any advice or tricks to this job would be much appreciated.
jlc

You'll need to pull both valve covers, and all of the accessories from the front of the engine. Not an overly difficult operations to roll in a new chain and replace upper guides. The reason for pulling all the accessories (PS pump & bracket, alternator & bracket, cruise actuator [plus I pulled the distributor]) is to access the guide pins.

A chain guide is prefered for rolling in the new chain, as that keeps the chain from jumping a tooth on the cam, but with care and patience (plus a lot of zip ties) it can be done without one. There are three upper guides you want to replace, one in the right head and two in the left head. I found it easier to replace the guides before rolling in the new chain. Be sure to mark the cam sprocket and chain at the left head as you need to remove the sprocket to access the two guides.

Hope this helps.