We have an 06' Tundra that started making a noise about 2 or 3 years ago. It was faint & it did not happen all of the time. As time went on, the noise increased in volume & started to develop a pattern. Turning, starting, stopping, & changing directions. This was more prevalent at lower speeds.
I had our mechanic actually lay on the ground next to the vehicle to listen to this noise. Laying on either side of the truck, it always seemed to come from the transmission. The next step was to take it to the dealer. They said it needed ball joints. I took the truck back to my mechanic who checked the ball joints & found nothing wrong with them. Surprise, surprise.
Nita got on-line & found a Toyota service bulletin. T-SB-0067-09 titled "Clunk Noise at Low Speeds when Stopping or Turning". There is a problem with the rear engine mount. Actually the mount for the tail end of the transmission. The TSB is for 05-06' Tundras & 05-07' Sequoias.
Since our truck is past it's warranty, I was able to get the dealership to sell the parts for cost +20%. $84 for the mount & 4 re-engineered mounting bolts. The bolts that hold the mount to the cross member. The service bulletin says to replace the frame cross member also. I chose not to. I will re-post if there is a need to.
Short of getting a set of calipers, I did not see an obvious difference of the mount. The mounting bolts have a larger contact area on the head as well as larger washers. The length was slightly longer also.
After doing the change out & looking over everything I wonder if a bit of thread locking compound & re-torquing would have been sufficient. 3 of the 4 mounting bolts were hand tight with the 4th one barely past hand tight.
I hope this helps with anyone that has a "Mystery Noise" in a 05-07' Toyota product.