Whenever I put my truck into 4wheel it starts making a wierd sound.It almost sounds like its just a cheap tin shield rubbing on something but im not sure. It still squeels even after it has been put back in 2 wheel. Im wondering if it is just some bad u-joints in the front drive shaft. Any info would be appreciated.

 

could well be...if it works ok,just squeals,i'd go there

 

Argon is on the right track. I had a squeel in the rear and ended up being my u-joints. The bearings probably went out on them.