W114 250 CE timing chain and tensioner replacement.

Dear all,

Today I replaced my timing chain and tensioner. 

I could only use the chain locking clips (circled in red) once while inserting the new chain while pulling the old one. After that, when I removed the clips, they bent too much, so I no longer trusted them for the final closing of the new chain. The old chain itself was about 5 mm longer than the new one.

For the old tensioner, I needed 3.0 kg to press the push pin in, and the new one 5.5 kg. 

Below are some photos with a detail of the one direction check valve (ball with holder). 

I have one question, although I don't think it's really critical. See the first picture: does anyone know the tightening torque for a, b, and c? I couldn't find them in the VdH flipbooks for my M114.980 engine. Thanks in advance, and enjoy the photos.


PS1: and i needed the Dremel tool to open the old original chain


 


Kind regards, Marc

Hi all,

And i found the instruction how to install and how to get the air out.

vdhflipbooks.de/books/WHB/WHB-ab-1968/#228/z


= install it without oil. then fill the tiny local bath with oil and move the end part of the tensioner by pushing on the tension wheel bearing.

Below two pictures. One filling of the local bath with engine oil with a syringe. Left of the syringe you see the top part of the plunger. The other is the edge of the bath when filled with the oil


 

Greetings Marc
 

Hi All,

And today I replaced the upper chain guide rail using a homemade tool to pull the two pins out of the cylinder block.

I do have a question: the car had a cast aluminum alloy rail (at least I suspect so) with rubber guides on the chain rollers. The new one is made entirely of plastic and slides on the links, not the rollers.

1)The upper pin fit neatly in the plastic, but the lower pin had a lot of play in the hole in the plastic guide rail. Is that normal? Is it supposed to be that way? The old one (original, I think) feels much more robust.

Regards, Marc

   

Hi Marc,

I had same old robust aluminium guides on my 450 SL. And guess what: I kept them instead of plastic guides that would break 20 years later.

Hi Volker,

But how do I know exactly if the old aluminum one with the rubber sliding edge is worn out?

By the way, I think I've found the answer to the large clearance. I guess I didn't look closely enough; one hole is oval. This is probably to allow the plastic to expand with temperature fluctuations. 



Regards, Marc

 

Hi Marc,

if rubber on metal guide is not broken or strangely worn off, keep it. It will last longer than your engine.

Hi Volker,

Thanks for your quick reply. 
I took a closer look at the old chain guide (see the picture) and took some measurements. The coating is definitely not rubber, but it looks like bakelite. It's the material used to make door handles in the old days. Perhaps someone has an original unused one lying around and can provide some comparative measurements. 

For now i will store my old chain guide on a safe place.

Best regards, Marc