I have a 2007 Brute Force. I went to plow yesterday after the heavy storm. While plowing my way out of the barn, the front wheels quit spinning. When I put it up on jackstands, all 4 wheels turn as they should and the 2 wheel and 4 wheel switch works as it should. If I put it in 2 wheel, the front quit spinning. 4 wheel, you hear the actuator engage, get the indicator, and the front start working. So I know the actuator is working OK. The problem is once it has to pull weight, they won't spin. It's like the clutch pack in the front differential is bad. I drained the oil, and flushed it out 2 times with new stuff, then refilled. Same result. The oil was almost clay colored. I am afraid it is the clutch pack but hoping someone has another idea. This thing only has 40 hours on it and I know I haven't swamped it. Thanks for any advise.