hey i noticed some weird noises my truck is making, it is not from the engine. i believe its from the mid to rear of the truck. when i hit the gas it kinda sounds like a card in your bicycle spoke, and when i feather the throttle it sounds a lot like a belt squeel. i checked the diff fluid its fine, and i pulled the tires and drums from the read and they look ok. nothing underneath looks broken or out of the ordinary. any ideas??

my spare was loose and hanging down, at first i thought that was it squeeling when it rubbed the frame, but i tightened it and its still doing it...

 

Check the u-joints first, and if they're okay you'll be looking for some foreign material you might have picked up along the way that's at fault. If there isn't any, it's time to get the truck onto a lift and in gear so you can isolate the noise with a stethoscope.

A cracked ring gear will make that noise, less frequently a broken tooth on a pinion gear will, too. Or it could be in the transfer case or overdrive unit, or a bad bearing somewhere. It's hard to know where to look until the assembly responsible for the noise is identified.