I have had this problem for a while but am new to this forum so maybe you guys will know. Every time I accelerate there is a clunk noise and I always fell it also. When I bought the truck back in 07 it was under warranty and took it to the dealership and they said it was the (slip yoke) and they said they fixed it. Well what do you know but about 1500 miles later after it was out of warranty it started happening again. It has never gotten worse but it super annoying. Any one have any thoughts? Thanks

 

If it is the slip yoke, it needs to be packed with grease. This seems to be a common problem on these trucks. I packed mine to eliminate the noise.

 

Yeah it just needs to be greased again. No biggie. Unless you u-bolts aren't tightened down or your have a lift with a really big block out back it'd be axle wrap. Grease it or do what I did and buy some spring clamps from an auto parts store and put them on your leaf springs about 4"-5" before the rear axle and tighten em down. Fixed my problem for the most part. Only on hard acceleration does it do it now but I wanna say that's axle wrap for me