Hi guys. In the course of doing a top end rebuild on my M104 I am replacing the timing chain, guide rails, and front timing cover seal.

The manual sections do not explain the correct order to install these parts (chain, cams, tensioner) if the old chain was removed and if the head/cams had been removed ALSO. The manual assumes you are replacing an old chain with a new one and it tells you to hook the old chain to the new one and feed it through. That won't work in my case because my entire top end was disassembled.

So - I currently have the head back on with the cams installed, but not timed. The timing cover is back on and the new chain is just hanging loose, not joined together. I went ahead and bolted the exhaust cam sprocket onto the cam but now I'm thinking I shouldn't have done that. So now I'm stuck. What is the next step? Do I do it this way:

1. Set the cam timing
2. Loop the chain over the sprockets
3. Install the chain master link
4. Install the tensioner.

Or, should I do it this way:

1. Remove exhaust cam sprocket off the exh. cam
2. Install chain master link
3. Put chain on intake sprocket and exhaust sprocket
4. Set cam timing and THEN bolt the sprocket back on to the exhaust cam
5. Install tensioner

Or is there another way? Just trying to make sure I don't screw this up. I have already screwed up enough on this job. I already had the front cover back on once and then I dropped the timing chain down into the oil pan. Was not able to fish it out, tore up the oil pan gasket taking off the front cover to get at the timng chain so had to pull the oil pan and change its gasket. ^%$#!!!

Thanks!!!! Pete

Option "A" would basically be the same method as having fed the chain through. At the end of the day you need your timing marks to line up, and I don't think that "B" is going help you do that any easier, so I'm sticking with "A". Final answer, Regis.

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Prost!

Thanks for the reply. I already tried this once (before I dropped the chain down into the oil pan and had to detour away from this job to pull the oil pan and retrieve the chain) and I was not able to get the chain to come together. It was as if the chain was 1/16" too short. I checked the new chain vs. the old one and they are exactly the same. I will try this again and report back. Thanks!

It sounds like your chain tensioner is already removed, correct? I can't think of anything else that would cause the chain to act too short, assuming it's going around the sprockets correctly.

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Prost!

Right, the tensioner is not installed. I might have had the chain hung up on the crank sprocket by a half link, I dunno. I will try it again and report back. Thanks!