Question: What parts do I need to order / tools need to own to replace the timing chain on an M104.980?

I'm looking the EPC and I see the following:



003 997 19 94 is the IWIS chain I need, but does it come with the master link 000 997 22 98? Do I need to order this?

Also, I have been seeing pictures of master links using circlips:



Is this what I will get if I order 000 997 22 98? Or do I get this:



If the latter, suggestions on a tool for crimping the chain?

I believe the timing chain on my M104.980 is stretched. The motor has 200k miles on it and I was initially set off to do a head gasket job. With the valve cover off, I set the motor to TDC by aligning the 4mm holes on the cams with the surface of the head. Further down the line of removing the cylinder head, I noticed the harmonic balancer was not at TDC where the front sensor is indicating. It was ahead maybe 5 or 7 degrees.

Here is where I am now, I figure it's super easy to replace the chain right now:

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Answered my own questions:

The JWIS timing chain comes with a link with solid pins that need to be peened.

First, I used a sanding belt dremel tip to grind down the old pins at any link. Then I used a hammer/chisel to pop the plate off one link and was able to remove the chain in 1 piece.

Ran the new chain and put the new link in place. Pressed the new plate and then peened the chain pin with a factory tool. Measurement of pin before peening was 3.30mm with digital calipers. Factory peened pins measured 3.60mm and double checked that my new link was also about 3.60mm.

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Those plastic guide rails are usually replaced at the same time, at least on other models. Not a lot of M104 chain replacements. Keep us posted and let us know if the stretch was eliminated.

__________________
Prost!

Here is a picture of both chains laid next to each other. The top one is brand new, bottom is the old 200k mile chain




The old chain was stretched by half a tooth.

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It is likely that the HG was replaced before. perhaps someone didn’t set the timing correctly?