Could still be u-joint...rolling back in neutral there is no pressure on the joint....does it squeak when you are just starting off.should be kind of a chirping sound like a small bird?? Try backing up a slight incline..how many kms or miles on truck?...my factory u-joints are all greasable
The sound is comming from the area of the front u joints, there are no grease fitting on them. I have 112000 miles on the Taco. It squeaks all the time in reverse and you describbed the sound. Sounds like I will be replacing the u joints. Thanks for the help!