Recently, I had an issue by where my 1994 G-Wagen (M104 engine) ran between 110C and 120C, particularly during uphill climbs and at slow speeds. After some research, I diagnosed the issue as a defective fan clutch.
Thus, replacement of the fan clutch was in order.
The MB part number for the fan clutch (as found in the G320 with M104) is the same as the normal M103/M104 part -- 103 200 11 22. The current MB list price (as of June, 2014) is $292.00. The unit I received from MB was manufactured in Germany by Horton.
Here is a photo pictorial of the steps required to remove and replace the fan clutch in a 1995 G320 (M104 gas engine). I hope this is helpful to someone in the future.
Tools required are:
- a 90-degree hooked awl-type tool;
- a flat-blade screwdriver;
- a 7mm Allen key (long is better);
- and the special 7mm MB "stubby" socket for the fan clutch bolt (this is not required but makes the job a bit easier).
It's also a good idea, before starting the job, to insert a piece of cardboard on the backside of the radiator to protect the fins from any accidental bumping or gouging from the Allen key and socket used to remove the fan clutch center bolt.
Here's an overview of the fan clutch area.
Remove the fan shroud by releasing the top retainer.
Twist the smaller (rear) portion of the fan shroud and move it backward over the fan toward the cylinder head. Remove the two metal fan shroud retaining clips on the sides of the shroud. A small or medium flat-blade screwdriver makes this job a simple flick of the wrist.
Carefully lift the larger (front-most) portion of the fan shroud upward and lift it out of the engine compartment
Move the smaller portion of the fan shroud forward off of the fan, and lift it out of the engine compartment.
Using the 90-degree hooked tool, wedge the end of the tool through one of the holes in the base of the emergency pin piece and in between two of the aluminum fan clutch blades. Turn the fan slightly to solidly wedge the tool in place.
Carefully insert the short end of the Allen key into the center fan clutch bolt. Turn the Allen key counter-clockwise (as you face the radiator from the front of the vehicle) and loosen the center bolt, holding the handle of the hooked tool in the other hand to keep it securely wedged into place.
Remove the Allen key and insert the stubby MB socket into the center fan clutch bolt. Turn the socket with your fingers in a counter-clockwise direction to remove and then extract the bolt. If you don't have this socket, you can remove the bolt with more turns of the Allen key, until you can grip the head of the bolt with your fingers to remove it.
IMG_5548.JPG IMG_5547.JPG IMG_5546.JPG
Remove the bolt and then CAREFULLY wiggle the fan/clutch assembly back and forth to loosen it from the pulley. DO NOT let the fan/clutch assembly touch the back of the radiator so as to avoid damage to the radiator and/or cardboard protecting the fins.
Once the fan/clutch assembly is removed, use a 5mm Allen key to loosen and remove the three bolts holding the clutch to the fan.
IMG_5525.JPG IMG_5526.JPG IMG_5527.JPG IMG_5528.JPG
Use brake cleaner or other solvent to clean the fan assembly, as needed.
Re-install the clutch into the fan, and then the fan/clutch back onto the front of the motor, using the reverse of the previously outlined steps.
IMG_5530.JPG IMG_5531.JPG IMG_5532.JPG IMG_5533.JPG IMG_5537.JPG IMG_5538.jpg IMG_5539.JPG IMG_5540.jpg IMG_5542.JPG