hey I have a 90' 240 and I'm a little green when it comes to a volvo engine. I'm wondering if tightening the belt is easy enough to do myself. Is there nothing to it? Or should I let a pro handle it

 

It is a basic setup. Loosen the bolt on the adjust strap, lever the alternator to get the tension and tighten the bolt. If the other bolts holding the alt in place are tight you may have to slacken them a touch.

Correct tension for the beltis measured at the centre point of the longest belt run. Using normal force the belt should depress about 5/16th inch or 5 - 10 mm.

 

The alternator has an adjusting bolt, about 3 1/2" long. Turn it clockwise to tighten the belts and CCW to loosen the belts. But first you need to loosen the set screw that holds the adjusting bolt. And you need to loosen the pivot bolt. If you don't loosen those bolts, attempting to turn the adjusting bolt will succeed in snapping the adjusting bolt and they're not easy to find.

The power steering pump has a similar setup.