My 1990 240 B21E w/ 90,000 miles squeals like a stuck pig for 30 seconds after starting. I’ve loaded tested the battery and replace ALL the belts, the alternator mounting bushings and replacedthe water pump, front seals and timing belt while I was there. But the alternator stills needs weekly adjustments. Now after 3 months the adjustment screw is near the end of its travel. Can I go with shorter belts or is my problem indicative of something else of which I’m clearly ignorant.
Electrically the car is back to OEM after I spend a week surgically removing a metastasized infection of aftermarket stereo and car alarm wiring, which was apparently installed by community service workers on crack.

 

Yes I would install a smaller belt. It should not need adjustment that fast.