Just installed both lower ball joints on an 2005 F150 4x4. Now under part throttle load like when you just start an incline a metallic noise comes from the front wheel. Best way to describe would be something loose knocking around on the backing plate. If I accelerate it goes away, likewise if I decelerate. Tried applying the brake without letting off the go pedal and it did not stop. Could the vacuum operated hub be loosing vacuum and allowing the gear to come in contact? By the way this does NOT happen all the time. You never know when it will happen.
Thanks in advance.

 

yep...check and make sure you didn't either rip the vacuum line when you pulled the lower ball joints or make sure its seated right...

 

Yes sir, lines are good. Took it apart again...cleaned all surfaces put a thin film of grease on mating surfaces. Still makes this noise. I read some where to replace the o ring when ever the hub is disassembled but the actuator is a sealed unit. I can not believe this thing is so sensitive.