There is a hidden bolt. It is located below the water pump and is usually a 19mm head.
The shock does not tension, but dampen the tensioner.
The graduation is for proper tension.
If the belt is loose, the tensioner is bad.
Have it replaced. If you want to do it yourself, it will take a while.
We sell them in the partsshop.
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
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