4 wheel drive wont

[Ronbo]

I have a Nortrac (Jimna) 254. It is a good tractor with no real problems, until now. If I put the front end in the pond and place it in 4 wheel drive, the rear wheels spin and the front don't. If I raise the front wheels and try to rotate them, I can't. If I take it out of 4 wheel drive, Ican then rotate them.

Any ideas? How do I tell if the front driveshaft is rotating inside the hose and metal tube? What is the most likely cause? I have an extended warrenty, but if it is something minor I can save the deductable.

Ron