I know it been talked about many times but I'm new here and don't really know how to work everything yet. I got my 04 f150 5.4 3V 4x4 6 months ago. I noticed the other week my right side AWI actuator was broke. I replaced it and found my left front tire spins freely while my right front tire doesn't. I found I had no vacuum to either actuator. Through some investigation I found my check valve was clogged. After I fixed that I drive the truck and found the passenger side was grinding only under acceleration. I locked the truck into 4 wheel drive to get home so I wouldn't destroy my new actuator because they aren't cheap. As I drove before turning into my driveway I put the truck back in 2wd and when I turned it was binding up. I put it back in 4wd drive and back into 2wd again. I unplugged the vacuum line from the intake and plugged it so I can still drive the truck without breaking anything. What am I supposed to do at this point? Iv been frustrated with the 4 wheel drive system for weeks now trying to figure everything out.

 

https://www.f150online.com/forums/ar...then-some.html

 

That is the guide I used on mine. You probably should have replaced both actuators and the solenoid. If it is the original one it probably needs to be replaced. I had to replace all three on mine shortly after I purchased the truck.