Recently as in the last week started to hear a hard clank and thump when slowing no brakes pressed or accelerating, speed seems to be between 30-40mph it only lasts for a few moments at a time. Seems to do it more noticeably when in 4WD auto, I took into the factory dealership immediately as it is just under 36K miles. The shop has been unable to duplicate although I took a S.A. out and they heard it. It doesn't sound like it's coming from the front of the vehicle and I havent had any luck capturing on camera yet. Any help would be appreciated...