Well, I finally took my 4Runner into the shop today. The road noise was unbearable. From 5mph up, the whir would start. Makes the noise while in neutral and when decelerating. Online research suggested either pinion bearing or carrier bearing. After inspection it was determined that it was 1 of 3 things, which by the way, are all costly. 1) Front Pinion Bearing=$835+tax 2) The 3rd member assembly=$1,358 3)Axel Bearing=$921!!!! :moping: I am currently waiting for the tech to call me back, but they are going to have to open it up to fully determine what's going one. The tech is leaning towards the #1, which is most likely the cause. The fluid was changed 30K miles ago with Mobil 1 diff fluid. The plug had no metal on the end when changed last year, so I doubt the 3rd member assembly will be required. The dealership admitted that there hasn't been hardly any cases of this on my gen 4Runner. It has never towed anything in its life, but parts are parts, and they will fail sooner or later. I am just glad I am getting it taken care of before a possible diff lockup, which could cause either a wreck, or destroying itself and doing more damage. Sucks because I have no truck for a couple of days. I don't have any extended warranties, and this is the first major issue to arise. Also forced to take it to dealer, many people wouldn't touch the thing. Said Toyota's setup is too complicated (granted I live in MS...) I will keep everyone posted. :violin: