Had a nasty belt squeal for a while. Kinda embarrassing to drive since it was louder than the engine itself. I could spray water on it and it would quiet down so I figured it's the belt. Bought the one in the picture from Rock Auto and the squeal is gone! Even the signature Cummins chirp on shutdown has gone away. Time will tell how it holds up. Just wanted to share for those fighting a squeal.

Been through to two belts now. Still the belt squeal in my truck does happen it can be just as a simple as replacing the alternator and the pulley is painted black. Now the paint comes off and glazes the belt. That's what killed my last belt was a new alternator with black painted pulley.

The “signature” chip at shut down I can live with, no problem. Mine is now constant and I think I got a bad Tentioner.  I went with the Gates HD belt and tentioner as their belts have served me well on my gassers.  I saw a Cummins tentioner for $188. Not ready for that swipe since many on Forum have indicated they run Brand X with no issues.  I had a squel shortly after installing new belt, followed Moparmans suggestion and reversed belt.  Problem stopped. This noise is constant and different. 

I've never replaced the entire tensioner, only change to a new wheel with the bearings. Last one was 29 bucks or so. I place the tensioner in the vise to unbolt the wheel and replace. It takes a star type torque tip to get it off. Take the tensioner with you to get the right size tip.

Edited March 17, 20196 yr by JAG1