I have a 2010 Toyota Tundra Limited crewmax making the above noise. It appears to be coming from the rear of truck. Iíve stethoscoped the rear wheel bearings and pinion bearing and all appear to be okay, nothing out of the ordinary. Replaced the carrier bearing as that was shot along with the u joint that was there. I canít seem to find the source of this for the life of me. The previous owner had an add a leaf on the truck to tow a fifth wheel and dropped the carrier. So I donít know if that may of did some damage to the rear end or what. I am running Yokohama geolander HTs in stock size if that helps any. When I drained the diff fluid I didnít notice anything out of the ordinary, no metallic sheene to it. Any ideas?