I'll give you an example of a problem I had yesterday. I have a hill at my place, just guessing here, is maybe a 15% grade, maybe a little more. I had my end loader on, empty and a home made ballast box on the back. The ballast box and the weight in the back was maybe 100 pounds. The hill had alot of leaves on it but it was dry. I forgot to put it in 4 wheel drive, and as I headed downhill, it pretty much just took off on me. What happens is the rear wheels lock up and you just kind of take off. I actually slowly stepped in to the hydrastat which got the rear wheels turning at least a little bit, and I was able to steer down the hill O.K. I have had the same thing happen on my old riding mower so I didn't panic. Its a helpless feeling. My hill isn't that long, about 70 feet and flat at the bottom. You could see the problem I would have had if the hill had been longer, if I had a loaded trailer behind me, and the trail wasn't straight. You don't want to be going 20 miles downhill in one of these things. I'm not trying to scare you, it just takes experience. Being a new tractor owner also, its best not to learn the hard way. I learned the hard way but wasn't hurt. I just need to remember, 4 low when going down the hill.