Ralph,
I'm not sure about other manufacturers' models, but mine (6-ft Bush Hog) has a slotted, pivoting linkage at the top link of the cutter. That linkage allows you to keep slack in your top link while you're mowing. The top link should be entirely slack during normal mowing -- and there should be enough slack in the connection to allow the cutter to tip forward and rearward as you go over hills and through dips. When you lift the cutter for transport, the first couple of inches raises only the front of the deck until the slack is gone from the top link, and then the tail wheel comes off the ground.
The manufacturer claims there could be a safety issue in using a chain for the top link. If the front edge of the mower happened to snag on a large rock or stump, it could theoretically cause the mower to pivot around the lift arm pins -- raising the tail wheel and deck up overhead and into the operator area. I don't know how likely that risk is, but I thought I'd mention it.
Setting the cutting height is a combination of two steps:
1) setting the rockshaft so that the lower 3pt hitch arms hold the front of the cutter at the appropriate height on a level surface, and
2) adjusting the tail wheel so that the rear of the cutter is 1-2" higher than the front.
Of course, the actual process goes in the reverse once you're familiar with it -- first adjust the tail wheel to about 1-2" higher than you want to cut (hard to do without lifting the cutter to take weight off of the tail wheel), then adjust the rockshaft lever so that the front of the mower is at your desired cutting height. You can then set your rockshaft level stop at that point so you can return to that height after each time you pick up the mower. What I'm trying to describe is that "leveling" your cutter is accomplished by adjusting only the lift arms and the tail wheel -- with the top link slack.
Although the manufacturer recommends setting the rear of the cutter 1-2" higher than the front for easiest cutting, I reverse that arrangement when cutting at a height of 3" or less. With the front of the cutter less than 3" off the ground, the front edges of the cutter tend to bite into the ground as it swings sideways when making turns across uneven terrain. By raising the front of the cutter to about 4-5 inches, the problem goes away. I can still maintain the 3" cutting height by setting the tail wheel so that the rear of the cutter is at 3". The tail wheel and the rounded shape of the deck in back keep the rear from carving up the ground during turns. Of course, this method takes more horsepower and uses more fuel (each bit of grass gets cut multiple times as the cutter passes over), and it's unnecessary if your land is nice and smooth.
I notice you're from Charlottesville -- I'm about 45 minutes east of you. Nice to have a neighbor with the same kinds of tractor questions I have.
Parker
