drumming sound coming from rear of truck

[ctrenary]

I've got a really strange drumming noise that is really loud. The noise seems to be coming from the rear of the truck. It is a fast paced drumming sound almost like two pieces of metal hitting each other. I just got the truck back from the dealership to fix a clunking noise when hitting bumps that turned out to be the caliper bracket. Unfortunately this drumming noise is very intermittent and this hasn't happened for a couple months. Today it happened when I was pulling out of a parking lot and there were no bumps. It lasted for roughly a mile before the noise stopped. The noise persisted when I applied the brakes or gas. It seems it only really happens when the truck has been sitting for several hours.

 

Here is a list of things that have been replaced within the last few months:

• shocks (all four)
• brake pads (front and back)
• rotors (front)
• hub assemblies (front)
• caliper bracket (drivers side rear)
• tires (front and back)

I've read many threads to try to figure this out but my issue seems slightly different. Any help would be appreciated.

[ctrenary]

found out the issue was the parking brake.