I've got a 2005 supercrew 4X4. I have a clunking sound from about 0-20MPH...after I hit 20-25mph it either goes away or I can't hear it anymore. It does not do it all the time so its hard to find where it may be coming from. I can tell its coming from something that is rotating because it has a rhythm to it...the clunk increases and decreases as I speed up or slow down. Seems like when its colder outside it does it more but could be my imagination. Can't tell if its from front or rear of truck. I don't think its the hubs because it does not grind and I have put it in 4wd and it still does it. I have replaced the 4wd solenoid and a portion of the vacuum line with no luck. I have also taken it out of gear and put the gear shifter in 2 and still clunks so I don't believe its the transmission. There doesn't seem to be any play in the drive shaft so don't think it is u joints. I am just puzzled to where it may be coming from. Can anyone help?

 

clunk like metallic sounding, or thud? If thud, sounds like tire flat spotting.

 

its kind of a metallic sound...but if it were the tires it wouldn't stop around 25MPH. I would think it would get worse the faster I go.