Truck making odd noise

[imported_cinder]

Vehicle Info: 2001 GMC Sierra 4.3L V6 Single Cab Stepside with 95,000 miles
Goodyear Tires rated for 100k mi. rotated every 8k mi. and have had for about 24k mi.

I have a rubbing sound. It sounds like the tires are rubbing on plastic. I can't seem to find anything on the vehicle that is getting rubbed. When I get out of the truck after driving I can't smell anything like burned plastic or rubber from fast rubbing. I do hear less rubbing when I take turns. So I'm almost positive its the tires or something related to them.

I also have a problem starting the truck too. Seems that my alternator is acting up. I jiggle some wires, tap the alternator with my palm a couple times and and starts right up. This problem only happens 1 of every 15 starts. I also might have linked the starting problem to my sound system. I have a 400 watt 4 channel amp and a 500 watt mono amp with 2 6" Door speakers, 2 4.5" Rear Speakers, 2 High End Tweeters, 2 10" Subs and a pioneer deck. I figure I might be pulling too much power from the single car battery and original alternator on the vehicle.

I was curious if the starting and the sound could have any relation at all either. I think I ruled out bad belts too. I hit the gas while in neutral and can't hear the rubbing without the car actually moving. A friend mentioned maybe a bearing. I don't know where to look to research that or find out info on how to replace it if that is the problem.

Any suggestions and I will be grateful. Thanks.

 

[imported_cinder]

no one can help me D:

 

[CoachB]

Cinder,

A long shot but maybe something to look into....
I had a pickup that had a bearing inside of a rubber bushing about mid-point of the drive shaft. The bearing started spinning inside the bushing causing a noise something like you describe. It would only do it when the drive shaft was spinning (i.e. the truck was rolling).
Another thought is maybe check your motor mounts. The engine could be shifting under load letting something rub under the hood.

Like I said...a long shot!
Good Luck

 

[Squisher]

For front bearing lift the vehicle, grab the front tire by the top and bottom and feel if there is any play. While you're at it spin the wheels and see if you hear anything.

In the back again lift both wheels off the ground, spin the tires by hand. and see if you hear anything. See if you see any play in any of the U-joints. *DO NOT START THE TRUCK AND PUT IT IN GEAR TO SEE IF YOU CAN HEAR ANYTHING* If you think this might have to be done, take it somewhere where they can lift it far enough so as not to provide a pinch point.