So im on the beach and turn on my 4x4, its all great until i start hearing this odd noise which if I had to describe...it sounds like chains being dragged on payment....i turn the 4x4 off, and the noise goes away. I also tried turning it on while in motion, but as im slowing down...i hear grinding and something similar to 4 low engaging, that THUMP. I believe my 4x4 no longer works...according to the dealer, a guy suggested to me, that the only true way i can tell wether my 4x4 system is running is to turn it on and turn my wheel all the way to one side and see if the truck will move...if it does not...or hesitates, the system works...otherwise the system did not engage. He did tell me not to force it and not to do that often, but to test the system is perfectly safe.

Now...i can hear everything "engage" if i turn on my 4x4 while moving i can feel it kick in, but according to the "test" the dealer told me to do...its not. I can also hear the 4 low engage.

So...whats broken so that i can fix it...with out my 4x4, i just have a truck.

 

The best way to see if it still works is to jack the truck up... all 4 wheels in the air. Engage the system (with the engine running) and look for items turning. At least one wheel in front may be able to rotate, but not both. The fact it'll be in park should prevent that. If you can rotate the wheels by hand, then look underneath and check for front drive shaft rotation. No rotation, then the problem is at the disconnect (diff engagement fork might be broke). If it's rotating then it's the transfer case, sounds like the chain. There's also the possibility that the drive motor that spins the driveshaft up to speed or the engagement motor that shifts the xfer case is bad.

Check this post out for how these systems work: http://www.fordtrucks.com/forums/sho...d.php?t=309867

The explanation came directly from the tech manual.

As far as turning the wheel to see if it will move... I think we are trying to bind the system up on pavement. Since the inner and outer wheels rotate at different speeds, so do the front and back axles. IF you drive with the truck in 4 wheel with its kind of set up, it'll bind. Perhaps if you bind it and see if it rolls on its own your are unbinding it? I've never heard of being able to tell if the system works using that method.

Hope that helps.

-Kerry