Suzuki: 4wd, auto hubs, wheel hubs

Question
2000 suzuki grand vitara the front axles are turning when i put the car in 4h but not th wheels? a mechanic told me front diff is gone and has to be replace.need your export openion
thanks

Answer
If the driveshaft from the transfer case, and the axles out to the wheels turn, the differential is ok, unless it sounds like it's trying to grind rocks.  That would be much more likely to be a front hub problem. (the auto hubs are somehow not working, and transmitting power from the axles to the wheel hubs) Usually the auto hubs are not as long lived as manual hubs, but then you don't have to get out to engage auto hubs.