Rear Diff problem in my 2009 dc 4x4

Took my truck in to get the rear diff checked because I could hear a faint noise when coasting at 25 mph. Thought I would get it checked by the dealership before I changed the oil to synthetic in case they wanted to blame me for any future problems. Although it was a very faint noise that I could only hear when travelling on a smooth road, with the radio and fan turned off, they drove it and agreed with me and booked a future appointment to have the diff changed under warranty. When I questioned the service rep as to the extent of this problem among Tacomas he informed me that the factory's position on noise complaints with Tacoma rear diffs is to have the rear diff replaced. I have almost 40,000 kms (25,000 miles) on my truck (most of it on the highway) and I don't drive it hard. I would suggest getting your diff checked if you hear any noise. What is happening with the quality of Toyota products?

 

My ring gear:


wish my truck was under warranty haha ....