need help finding this whinging noise

[rocdamike]

Hey guys I need your help I have a whining noise sounded like it was coming from a wheel bearing so I replaced them then I thought it was a U joint so I replaced both of those and the noise is still there I'm out of ideas anybody now what it could be?

I own a 2002 Sierra 1500

 

[98trck]

serpentine belt start making noise when they are going bad and if it has never been replaced on an '02 its time, start with the simple thinks have you looked closely at your tires rotate them and see if that makes a difference

 

[RNeville]

Idle Tensioner Pully

Mine started whining (the pitch followed the RPMs) at about 150k. It was just the Belt Tensioner Idle Pully. I had them replace it along with the serpentine belt on my 150k mi service and the noise went away. Do some searching by placing a short length of garden hose to your ear and search around the engine bay with the other end of the hose. Originally the whine sounded like it was coming from behind the AC pump but ended up being the belt tensioner idler pully.

Good Luck!

 

[rocdamike]

The noise sounds like it's coming from the rear of the trick that's why I suspected the u joints but I can't figure out what it is it might be coming from the rearend