my truck has a new built tranny in it and it hits second gear so hard it squeels the belts it sounds like tires barking but its deff. the belts any fixes for this or sugg for whats going on?you can see where its wearing on the idlers .

 

your belt is slipping..
maybe a bit shorter belt..
also..
how many miles on the engine?
you could have a pulley wearing down that is allowing the belt to slip,

 

I just did a tranny on another members truck and the belt would squeal on every shift. It was shifting to hard in my opinion. After talking to the tranny company they suggested we remove the sonnax servo and install a vette servo. The tranny was built for a combo with a loose converter and numerically lower gears both of which would soften the shifts.

IMO soften the shifts and forget about the belt the rest of the drive-train will thank you