so I'm driving down the road last week when they thawed out and dried up and i hear a clunk when i take off then again after i stop and turn.
ok so i think its my ujoint so i went home and got underneath and checked em there isnt any movement in the ujoint but i hear the clunk when i move the drive shaft. its comming from the rear dif any ideas what it is?
oh ya... its a 97 f150 4x4 flare

 

Pull the drive shaft and check the pinion nut on the diff. Do it soon, if it's loose it could have a catastrofic failure in the diff.

 

^agreed^

 

thanks all but it ended up being the rear ujoint after all there wasnt any play but when i got under ther again I found it locked up ... weird. but so ya its fixed now thx again.

 

Thanks for posting what the problem was. Helps us help other people.