The nut that you tighten that is suppse to sinch down the alternator so it does not move keeps comming loose, thus the belts keep loosing tension. This happens within ohhhh maybe 75 miles of use. This nut is on the bolt whose head has the adjusting rod attached to it.

Any suggestions? Especially since I got a thousand mile haul comming up.

THANX IN ADVANCE!!

__________________
"If anyone knows other lessons I need to learn, please tell me. I'm tired of learning them the hard way".
by JerryBro

The Glow Plug Wait: This waiting period is a moment of silence to pay honor to Rudolph Diesel. The longer you own your diesel the more honor you will give him". by SD Blue

My normal daily life; either SNAFUed- Situation Normal... All Fouled Up, or FUBARed- Fouled Up Beyond All Repair

62 UNIMOG Camper w/617 Turbo, 85 300SD daily driver- both powered by blended UCO fuels

coachgeo,

I think there are three fasteners involved. One is the unit that is connected to the mechanism that moves the alternator in and out. Then there is at least one more at the pivot point that has to be cinched down, and then I believe some alternators have a third fastener that rides in a slot that has to be cinched down too. The one to turn the alternator on its pivot point and change belt tension is not good enough to hold it in position.

The unit at the pivot point comes with a sleeve around it that fits between the ears on the front and back of the alternator. Without this sleeve I think it is possible to break an ear off the alternator or at least bend one or both of them.

Check out all the fasteners though. Good luck, and I hope this helps, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Thanks Jim. The top bolt the alternator pivots on is TIGHT as it can be. It does not move at all. Now to find that third thing (not inlcuding the actuall adjusting nut)

__________________
"If anyone knows other lessons I need to learn, please tell me. I'm tired of learning them the hard way".
by JerryBro

The Glow Plug Wait: This waiting period is a moment of silence to pay honor to Rudolph Diesel. The longer you own your diesel the more honor you will give him". by SD Blue

My normal daily life; either SNAFUed- Situation Normal... All Fouled Up, or FUBARed- Fouled Up Beyond All Repair

62 UNIMOG Camper w/617 Turbo, 85 300SD daily driver- both powered by blended UCO fuels

coachgeo,

I just pulled up the photo on Fastlane of the alternator for the 240D. This unit has no third fastener, so I may be guilty of misleading you.

The way it works on a 240D is pretty straightforward. I just checked as the car is home now (the wife and daughter made it back from San Diego yesterday), and the lower fastener releases the mechanism to pivot and the upper one on this bracket gets loosened to allow a nut to be tightened to pull the unit in the tighten the fan belt direction or force it to push in to loosen the fan belt. Both have sleeves over them to prevent bending the bracket or breaking one of the ears off. The third bolt I was confused by is the one that holds the bracket to the engine.

On my cars you have to loosen the pivot point to get the alternator to move at all. I know from experience with the sleeves missing from the bolts, the system does not work. I would check to see the sleeve is there on you pivot bolt and the tightening bolt. I broke an ear off once without the sleeve so be carefull. Also make sure that third bolt is tight or the bracket may be moving as well.

If the adjusting bolt is loose then you probably need a lock washer. Same for the pivot bolt. Hope this helps, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)