suspension/driveshaft "knock/clunk" 06 prerunner DC

Got a question.

Have an 06 Prerunner DC, with only about 31k miles. About 4 months ago I bought 4 new tires (Michelin's). While the truck was at the mechanic, they also did a f/e align, changed front brake pads and adjusted the rear brakes. Ever since I had the work done, I have noticed a loud "clunk" or "knock" coming from under the vehicle when I accelerate or take off from a stop. Sometimes also happens going over bumps. It is sometimes a single clunk (like metal on metal) but can be a series of "clunks".I tried to isolate the location of the noise (by having the wife drive with me in the bed) but it appears to be coming from both sides, but I cannot tell exactly where (more towards the middle). I took the truck back to the mechanic (who I really like. I am an auto claims adjuster and send a lot of work to him), and they kept the truck for 2 days, and while they were eventually able to reproduce the noise, they could not give me a definite cause. They said it may just be some play in the driveshaft. It is really annoying, and is VERY noticeable when driving with the windows down. I have searched extensively here and all over the net and cannot find any answers.

Any input??

 

Could be U-joints or axel wrap.

 

I vote U-Joints, although they should've lasted longer. Get a pic of the joints on the front and rear of the shaft and upload so we can see. Don't need to take the shaft off for the pics. I'd like to see ith there is spacing between the grease bushing and the body of the joint.