You will get not only belt replacement instructions, but also instructions for changing the thermostat, the A/C idler pulley, and the fan clutch, as well as tips and tricks to do these jobs successfully without breaking anything or pulling your hair out.
If you have no idea when this pulley was last replaced, just plan to replace it when you do your V-belts. The bearings can get quite noisy long before it actually fails.
Location of the idler pulley.
Four new Continental belts with detailed video instructions. You should consider replacing the following at the same time, as they are commonly due to age and neglect.
In this 16-minute video, Kent explains the two upgrades he made in early 2026 to his electronic fuel injector tester. This video is specific to the tester we sell on this website. See related products below.
Genuine Mercedes new part a shown, but does have some shelf wear. This has been sitting in a dark and dry garage for about 20 years. It was mounted on an engine out of the car but not run. But it was put together with the housing and then taken apart.
When you download this from your "account" at Mercedessource.com you can print it on standard 8 1/2 x 11 paper, or you can view it from any computer if you are logged in at Mercedessource.
This can be used on older 4, 6, and 8 cylinder gas engines up to around 1991 (end of W126). This works particularly well on the M116 and M117 V8s from 1972 to 1991. On some early V8s, you have very limited room to get to the rear sparkplugs. You can use the short extension.