I have a 03 Ford f 350. When i put my truck into four wheel drive it goes in but when driving down the road the four wheel drive stops working. does anyone now what may be the problem.

 

It could be any number of things, but I'd guess that you have a problem with your lockout hubs. Do you have the electronic shift four wheel drive?

I would start by shifting into 4-hi and driving until you lose four wheel drive. Then take it back to the house and jack up each wheel end and see if both axle shafts are spinning when you spin the tire.

 

Welcome to FTE.

What makes you think the 4x4 stops working?