How to Change a Drive Belt on 1992 Mercedes 300E

1. Park the 1992 Mercedes 300E and open the hood. Look on the under side of the hood or on top of the fan shroud for the serpentine belt routing diagram. Use this diagram to install the new serpentine belt.
2. Remove the fan cover behind the radiator by pulling the locking pins outward. Then, pull the fan cover off and out of the engine area. Use the pliers to pull the locking pins out if needed.
3. Look on the very front of the engine and locate the adjustable tensioning device. Follow the device up to the top of the engine and you will see the adjustment nut for the tensioning device. Loosen this nut with the 1/2 inch ratchet and a socket to loosen the serpentine belt.
4. Remove the serpentine belt from all of the pulleys and pull it out of the engine area.
5. Route the new serpentine belt into the engine area and wrap one end of the belt around the bottom crankshaft pulley.
6. Route the new serpentine belt around the other accessory pulleys, including the tensioning device pulley. Use the serpentine belt routing diagram for the directions.
7. Look over the belt to ensure that it is properly routed. Then, tighten the adjustment nut clockwise to tighten the serpentine belt. To test the tension of the belt, push down on the new belt with you hand. The belt should not have more than a half inch of slack in it.
8. Crank the 1992 Mercedes 300E and watch the new belt as the motor is running to be sure that the belt is properly seated in the pulleys. Then, put the plastic fan cover back on. Close the hood and turn the motor off.