I have replaced the diff, pillow *****, diff mounts and trailing links. None of which were related to the noise however I thought it was important.
When driving down the road, smooth or rough, there is a rather continuous knocking noise in the rear. If I touch the brakes or e-brake the noise goes away. Let of the brake and it comes right back. Rather annoying. I have not replaced any other parts in the rear except for that listed above. Let me know what you folks think.

 

Loose exhaust components maybe?

 

its not exhaust becasue its an all custom setup and I have checked the clearances on it I dont know how many times and it has done it since I bought the car 2 years and 3 exhaust setups ago. :-/