There is a clunking noise when both front tires are turned manually back and forth while jacked up. 2006 f150 4x4 xtl, 5.4l v8, 98k miles. Ball joints, control arms, struts, coils, drive shaft u joint, calipers, shocks, vacuum seal actuators, wheel bearings,rotors, and brake pads, spark plugs, coil packs all replaced. It seems to clunk upon acceleration from a stop, almost like its locked up. What could it be?

 

Check the cv for play at all unions. If none there, possibly extra play in the front diff. This is not uncommon if you have had different sized tires on the front for an extended period of time, or just use the 4x4 frequently.