2003 Supercrew 5.4 liter 4x4 having problems with the four wheel drive system. It all seemed to start after I had the driver side top and bottom ball joints replaced back in July. I never used the system until a month ago. Once I diengaged the 4x4 system on the dash .. it has electronioc locking hubs it made a loud whirling sound with some vibratins through the wheel. I eventually went away after 5 miles or so. I tried to use the 4x4 system yesterday and it seemed that it was engaging. I had physically lock the hubs then it worked. Then I had a hard time getting the 4x4 light off of the dash eventhough the hubs are unlocked and switch is turned to 4x2. I noticed today that if I turn sharp the fron end make a noise, almost a skipping sensation through the steering wheel. I'm at a lost and would like some advice where to start diagnosing this problem. Any response may help.

 

Could be either a vacuum seal issue in the hub, or a shift motor problem on the transfer case. Maybe even internal hub problem. First thing to do would be to scan it to see if there are any codes for the shift plates
or motor.

 

When I drove a Jeep Wrangler, I would experience the skipping sensation you described when the 4x4 was engaged and I made sharp turns. I wouldn't know if this is related though.