2001 B7500 4x4 not engaging

[Kgpitbull]

I have a B7500 4x4 and it won't engage in 4 wheel drive. It runs in both 2 and 4 wheel positions but only rear wheels spin. There is no noise or binding... the lever moves as it always has but won't engage. It Has the same ag tires from factory but my son drove it from the back of the property to the front on a flat left front tire one day. I wouldn't think this would cause it but IDK?? Any help would be greatly appreciated

 

[freewheel3]

Make sure it's not something simple like a sheared off or missing roll pin where the lever rotates the shaft on the side of the transmission.
I had this happen on an L185, thought it was something serious at first but just had to replace the lost roll pin.