So I put the foam peice back into my gimbal to protect it while it wasn't in use. Then I pulled out my trust Phantom and did a few flights, last flight it seemed to have gimbal issues. Then I flew it today and it said gimbal overload, so I landed it and found the foam still in it. I think my yaw motor is damaged, is that about all that it usually trashes? I build race quads and I am sure I will have no issues swapping a motor.

Why do you think it is damaged? Try flying without the foam and see how it performs.

I did, gimbal has no stability on the yaw axis and I get gimbal overload errors. I tried calibration and no change.

I'm sorry to hear the issue. It is not recommended to take apart at your end if the drone is still in warranty period. Please kindly start a case and send it in for diagnosis: https://www.dji.com/support

How long is the turnaround time and what is the cost of that? Would it have to be sent to China or is there a repair facility in the US?

DJI has a service center in California.  They will send you a repair quote with a list of damages and their cost to fix including labor.

I open a repair ticket but it has no address to send it to, Where do I send this thing?