1987 300D. I have a loud squealing from the front. Looked under the hood and it seems that the pulley directly in the center of the belt is out of line (the one marked #1 in the picture below). I think this is the belt tensioner. The pully is a $40.00 part and i'm sure I can handle it myself. But, do I need to remove the radiator, fan etc to get to it? Is there anything I can harm down there?

Joe

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1987 300TD 440K - My car
2005 Jeep Grand Cherokee Laredo 107K - Tim's car
2000 - CLK320 100K - Deb's car
1994 C230 150K - Josh's Car

Hello, I have same model and have begun to hear that sqeak occ. In anticipation, I have found advice on one of the other threads but cant tell you which. In escence, you can easily remove the fan shroud by pulling off the two clips up on top and sliding the shroud carefully upward. You might want to go ahead and remove the front engine drip pan first, just in case you cant get the leverage on the pulley nut from above. Next you remove the tensioner spring by removing the nut on top bolt, then with the lug wrench (issued with the car in the tool bag), put the end into the hole on the black bracket and with a little tension upward on the spring (be careful, it is some form of plastic), you can slide the bolt out of the bracket , then slowly release the tension with the lug wrench shaft. Remove the spring (it was just held on by tension). Then you can push the pully to the left which will release the tension on the belt. I believe you can then remove the pulley without removing the belt, as the loop will tend to stay in place if you do not dislodge it. The pulley has a plastic cap over the front of the shaft bearing which you can pry off. If you did not get a new cap with the replacement (I did not), then save it. The pulley shaft is held on by an allen bolt. Don't know what size but if you can match it and carefully crank it loose without gouging your fan, you have it. Having said all that, I would first check with Larry Bible or Gillybenz or Peter Frederick all of whom seem to know volumes about these cars and see if they would advise you differently as I am just an amateur. Good luck. Harvey

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hlg

PS Joe, when you get the spring off I would check and see if the pulley wobbles or if the whole tensioner assembly is out of line. That would be a different cookie but replaceable. Again I would double check with the good guys I mentioned on the first reply. Let me know how it goes. Harvey

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hlg

Bad tensioner pulley is farily common on the 603.

You must remove the fan. Take an 8mm allen wrench and a piece of pipe to unscrew the allen in the center of the fan. Hold the fan with a 3 mm allen stuck through the bracket from the back, there is a hole there.

Stick some cardboard between the fan and the rad to keep from denting the fins. Don't forget to remove it when you are done!

When you get the bolt turning, use the index fingers of both hands to unscrew it, you won't have room to get a singe hand in there AND turn the bolt. If MB had put a notch in the pulley, you wouldn't have to remove the visco clutch....

I'd pull the tensioner setup and inspect for distortion of the pivot hole, although the usual ware spot is the pulley bearing. If it is worn, the new pulley won't last long, as it will be running sideways.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Hello Peter, I was wondering what would prevent my pulling the pulley by itself. With the shroud out, I can certainly get to it for removing the allen bolt. Or will it move about too much? Or perhaps damage the assembly itself? The fan can be kept in such position as to allow the wrench over the center of the pulley (I think). Regards, Harvey

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hlg

I found out today there is more room up there than I though. It's tighter on the SDL than on the 300D, for some reason.

You can also change the belt and leave the fan on. You have to get the belt around the crank pulley from underneath -- took me less than 30 min to to the whole job while I was evacuating the AC today.

However, with the 8mm allen and something to lock the fan through the hole in the back, its' faster to remove the fan.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!