Yes, there is a dual range separator drive speed, high range and a low range. I don't really know how a 3D seive works but our 9750 has a stair-step rotary design that gives the crop mat room to to expand as it travels through the separator, also we are on mainly flat land. I honestly haven't ran it much, maybe a total of 15 to 20 hours. I usually run our 9610 or a tractor and grain cart. I'm still learning about the sts as well as my dad and brothers. The first two weeks we had it, I swear the Deere dealer was out everyday with us learning more about it too and they still come out. It must be alot nicer than our 9610 because we could hardly get our dad in one last fall, now we can't even get him out of the 9750. Now I have a tractor question for you. We had a 9400T the past two days just trying it out and we were very impressed with it we could pull circles around are 8970 4x4 even with it properly ballast and the 710_70R38 duals properly inflated to 7 psi in the front and 6 psi in the back. Note the 9400 was not even ballast for fall work. My question is have you ever ran a 95E ChallengerIJ We tried to get one from the Cat dealer and they would not let us try one because we used two challenger 55 for about 50 hours free of charge about two years ago. We were really impressed with them a lot but do to the fact that the closest CAT dealer was an hour and 15 min. away. We ended up trading for a 8200T and a 8400T considering there are four deere dealer within 30 min of us and the closest one about a stone throw away. We do respect there answer, but we do want to get some information on how much they are, we tried a challenger 65 about five years ago, are they anything like themIJ The deere dealer were saying the 9400T would run close to $180,000 and they were not really willing to deal with our 8970 with 3800 hours only offering $85,000 and we sure are not going to put up a $100,000 at this time, considering we paid about $50,000 trade difference for our combine and the 9610 we trade was traded last fall so it only had 7 engine hours on it, kind of stupid but what my dad wants he gets. Please let me know if you know anything on a 95E Challenger. I'll let you know more about the 9750sts as I learn more. Nice to Know we can have our differences and try to get a long. Hope to hear form you lexionman or anyone.