I had a heavy metal rapping coming from the rear axel on the ride back home last week, it only happened briefly a few times for 3 or 4 seconds each time, I eased up on the gas and continued home without any further noise, gave it some gas at the hill approaching the house and back it came, at that point I shut it down and got it to my local mechanic. I thought it was a CV joint or an axle end, but it turned out to be bad u-joints and the metal mounting plate that secures the differential being ripped loose and depending on the terrain and my speed the differential would bounce up and down on the frame. He believes that the bad u-joints caused the differential to have an oscillating motion placed on it which caused the metal to rip free from the frame, I feel the metal plate was weakened by the upward force exerted on it by the rear wheels repeatedly pounding holes and other obstacles eventually causing the metal to fatigue and rip free allowing the differential to float around and wear out the u-joints. New u-joints are coming from the U.S. this weekend and a heavier mounting plate was already installed .....hopefully all else is good. I attached a picture and you can see where the metal is missing and a number of cracks in the plate, in the foreground is the piece that was ripped free while still bolted to the differential.