1999 Ford Explorer Front Axle

I have a friend who called me today, she has a 1999 Explorer Sport with over 200,000 miles on it. She said she was coming home the other day and as she was pulling into her driveway she heard a clunk then the steering kind of locked up, and it felt like a tire was dragging. She moved the truck later and said that it goes forward and backwards fine but grabs and skids while trying to turn.

She called her local mech, and he thought the diff could have given out on her and is basically acting like a locked diff rather than open… I think the front axle must have somehow engaged, and is stuck… So my question is this, how does the front axle on a explorer engage… I know on Jeeps and Chevys there is an actuator that moves an arm that moves a sleeve that engages both sides of the axle. Does ford work the same way?? It would seem to me that if the truck is going front and back fine the diff itself should be ok?? What are your guys thoughts??

PS the xfer case was replaced about 3 years ago.

Sounds like a U-Joint in the axel failed. Their at the end of the axel and before the spindle and the U-Joint can be seen in the opening. If it is broke you see that it is. Take a look and let us know.

I thought the explorer used half shafts in the front ??

The 99 has half shafts.
It has a vacuum solenoid actuator on the front housing.
Test it, test vacuum supply, then dig into the diff last.