I recently had to change out the serpentine belt on my 2010 Ram 1500 Hemi when the idler pulleys bearings went bad. During that process I also saw that the tensioner pulleys bearings were bad so I changed that too. With two new pulleys and a belt my truck is squealing like a pig at idle and seems to get louder with acceleration. The truck has just under 116K miles; anybody got any tips to fix this?

 

Seems like the choices are that one of your new bearings is bad, belt is not tensioning correctly or the belt is a little to long. Did you use Mopar parts, decent aftermarket, or the cheapest stuff they had at AutoZone?

 

It could also be possible that the belts are not tight enough.

 

Is the new belt routed properly? I'm not sure how many different ways I can go on but I do remember it being difficult to figure out without a diagram.
Also maybe one of the new pulleys didn't seat properly when you installed it or perhaps you got the wrong belt from the parts store. Is the tensioner applying adequate tension to the belt when installed?
When installed properly the tensioner should run somewhere close to the middle of its range of motion