I have a rattle in the rear of my truck, 03 extended cab. At first i thought it was the inserts between each leaf spring, went to replace them and they were still good. Next i tried the parking brake shoes and that while it helped my parking brake hold alot better didnt help. Wondering if maybe someone else ran into this before? Only hear it with window down, and after a slight bump.

 

Check sway bar hardware if it has one of those.

 

 

Check the exhaust to see if you can shake any part of it and it touches the frame. Had this problem when one if my mounting rings got weak.

 

Im gonna check the sway bars. I know for a fact it wasnt the parking brake. I fjgured it had to be the parking brake awhile back so i replaced them trying to beat the rain and it didnt help.