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Chain Tensioner/ Timing Q's

Started by Jenno1981, 24 October 2023, 02:44 AM

Jenno1981

Hi guys,

1979 450SEL w/ M117.983

Installing a new chain tensioner and I've got questions:

1. In the manual it says to submerge tensioner in oil... is it essential because I've already installed without this step.

2. There's a large external threaded hole on the outside of the tensioner just above the pin. What is it and what is it supposed to connect too? There was nothing installed on it previously when I took the old one out, it was however plugged up, is that essential?

3. The external section of the large pin on the tensioner has a hex and thread on the outside, it looks adjustable. If so, where should it be? I've installed it as is out of the packet.

4. Lastly, I've taken the lower oil sump off and there are fragments (small and definitely not complete) of a guide rail in there :o As part of timing chain service, I've replaced the 3 upper guide rails and can see the guide rail attached to the tensioner area looks intact, well the upper part is anyway. I've essentially finished the timing chain service, ready to put the covers back on. Any suggestions? How bad is it without one of those lower guide rails?

Cheers,
Jenno
1978 450SEL - Green
1999 ML430 - Also green 🤷�♂️

rumb

I would go back and oil fill per
https://handbook.w116.org/cd/Engine/107/M117_45/05-310.pdf.

Otherwise no tension on startup.

The lower guide fare much better as there is less heat at bottom of engine.

#2 see instruction, mentions foam vent or other vent for certain options.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

Jenno1981

Thanks as always Rumb.

Re-installed the tensioner as prescribed.

As for the rail guide fragments, will just have to kick on until the day comes where the cover is off to tell the story.

Cheers,
Jenno
1978 450SEL - Green
1999 ML430 - Also green 🤷�♂️

kosher

Quote from: rumb on 24 October 2023, 08:36 AMI would go back and oil fill per
https://handbook.w116.org/cd/Engine/107/M117_45/05-310.pdf/space bar clicker

Otherwise no tension on startup.

The lower guide fare much better as there is less heat at bottom of engine.

#2 see instruction, mentions foam vent or other vent for certain options.
As always, thanks, Rumb.
replaced the tensioner in the recommended location.
Regarding the rail guide pieces, we'll just have to keep going until the time comes to reveal the narrative without a cover.

Jenno1981

Quote from: kosher on 30 October 2023, 03:49 AM
Quote from: rumb on 24 October 2023, 08:36 AMI would go back and oil fill per
https://handbook.w116.org/cd/Engine/107/M117_45/05-310.pdf/space bar clicker

Otherwise no tension on startup.

The lower guide fare much better as there is less heat at bottom of engine.

#2 see instruction, mentions foam vent or other vent for certain options.
As always, thanks, Rumb.
replaced the tensioner in the recommended location.
Regarding the rail guide pieces, we'll just have to keep going until the time comes to reveal the narrative without a cover.


That's what I meant Kosher - thumbs up
1978 450SEL - Green
1999 ML430 - Also green 🤷�♂️