strange noise
 

My 08 XLT makes a load bang when i do a quick acceleration from a stop. it almost sounds like something is loose but I cant find anything.
The sound sounds like ti is coming from the back of the truck. I thought it was the spair tire but it is tight and doest move when I push on it.

any idea as to what I should look for?

Possibly a loose U-joint on the front or rear drive shaft. I'd also check the rear end (axle) mounts, shock mounts, and perhaps the emergency brake to see if the shoes/pads are hanging up within the rear disc.

this is a brand new truck only a few weeks off the lot.

I was thinking it has something to do with the auto locking feature on the truck. seams to only happen when I first start out and once the doors lock I don't hear it any more.

W A R R A N T Y

+++1 bring it in

I was thinking maybe it could be something small I am over looking.

or it could be normal when the truck moves and the doors lock

Sit in the truck and lock the doors. If the sound matches then you found your answer.

Bucko is right if it's an actual clunk from the the rear then any number of things could be going on in the drive train. take it in!

John