Fan Clutch Test and Fix

[mbboy]

I noticed during a search that many people have reported rising temperatures when stopped at a light, particularly when it's hot out and the AC is on, since my 380sl just started doing this.

One of the first suspects seems to be the fan clutch, and the preferred methods of testing it seems to be 1) trying to stop the fan with a rolled up newspaper, or something similar, when the car is hot, 2) seeing how easy it is to spin the fan when the car is cold and/or hot, and.or 3) determining how much air the fan is moving when the engine's hot. Since these methods don't seem to be very definitive, however, many people ended up having the same problem even after they replaced the fan clutch.

I therefore decided instead to remove the 4-12mm or 13mm (?) bolts that fasten the clutch to the water pump, which allowed me to easily slide the fan and clutch out of the shroud. I then carefully pried the bimetallic strip from its clip, making sure to note which side was up, and I removed the 8mm Allen bolt holding the clip on the clutch.

Following that, I place a thick plastic washer over the center hole in the clutch, I put the clip back on, and I tightened the Allen bolt hard enough to insure that the clutch was engaged to the extent that if it turned, so did the the fan blades. I then put the fan back on the car, and Voila! No more rising temps at stop lights, even when it's warm out and the AC is on.

I'm now debating whether to 1) just leave the clutch this way through the summer, as it will soon be warm enough to need the fan most of the time, especially while driving locally, 2) to replace it with a) an OEM (Sachs or Horton) for $200+, or b) an aftermarket unit (Behr or Uro) for under $100, even though I've read that people have had problems with these; or 3) to try fixing it by injecting high viscosity silicon oil into the clutch, as some people have.

I was therefore wondering if anyone here has successfully refilled a 107 clutch, or has had good or bad experiences with aftermarket clutches.

Thanks in advance for the info.