Hi. I have an '04 f150 fx4 s-crew. Had a funny noise underneath it almost like tin rattling. Thought it was a heat sheild rattling but after driving for a bit it got worse when you accelerated and went away when you put it in 4 high. Took it to the dealer and they replaced the vacuum solenoid. Yesterday the noise came back and tried it in 4 high again but this time it was worse in 4 high. Had it parked on the damp grass and went to move it ahead and all it would do is spin. So tried it back in 4 high and it made a high screech noise and the rattle was really bad and the truck would only spin and not go ahead.I could back up fine but not go forward.So I tried 4 low.As soon as I put it in gear it started "hopping" and made a loud bang. I ended up getting it towed across the yard and while being towed it spun the whole way . Drove it out the road after getting on dry pavement and the rear wheels seemed to spin even while driving slow. Had it towed to the dealer last night but was just wandering if anyone has any suggestions as to what this could be? I don't know much about vehicles but it is 5.4 , automatic. Thanks!