There are two ways to determine chain stretch. The first method is commonly called the 2mm valve lift method. This is the method that Mercedes Benz specifies. It will give you a highly accurate reading.
The second method consists of aligning marks on the front cam bearing tower and the sprocket thrust washer. This method can give you an accurate reading but it all depends on how accurate the marks are aligned.
It's not necessary to bring out the dial indicator every time you have the valve cover off. Aligning the cam marks is a good way to see where the chain is at.
I like to check with the dial indicator once maybe twice a year to get an accurate reading.
Ok lets get started.

1-The first thing to do is remove valve cover. It will help putting things back together if you take pictures.



2-Setup intake valve #1 pointing up in relation to rocker arm. Intake #1 is the second valve from the front.



3-Just remove valve lash.



4-Remove magnetic base from dial indicator post holder and install as shown. Use channel locks to gently make sure it's tight.



5-Setup your dial indicator. It will take some finagling but it will work.

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1984 300SD Turbo Diesel 150,000 miles

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