On our 26 mile mine trail there a few boulder alleys. The boulders dented the side of the rims in a few places. We pulled a heavy tracked trailer and hauled a full load. It made the trip perfectly. We crossed a creek in about 36 inch water. Still no problems. But now I see the front seal at the differential is leaking oil. We also had trouble climbing the steep hill behind our mine. The unit seemed to stick in high or second and wouldn't spin the tires in gravel. It stalled out so we backed down. A dealer in Delta Junction told me they learned the hard way but you have to tap the brake to make it shift down. I would prefer a method of locking the unit in low gear or even a lower low gear.