Don,
I have a Woods 7500 backhoe on my Kubota
B2910 and am also well familiar with the ability of the hoe to pull the tractor around. Our clay soil is filled with rocks too, so I think we have similar digging situations. Some things I've learned:
As soon as I feel the tractor move, I let off the backhoe controls and try to reposition the bucket to get a different "bite". Sometimes this requires several smaller bites to uncover the rock enough to pry it out and remove it.
If the tractor set-up does shift, you can often reposition it by using the hoe. Use down pressure on the boom to lift the stabilizers and rear wheels of the tractor and the dipper and/or swing to put the tractor back where it was. I have a sub-frame on my tractor, so I feel pretty comfortable doing that, I don't know if that's a good practice without a sub-frame. The Deere hoes, from what I've seen and read, are a pretty nice set-up so I don't think that should be a problem.
As others have suggested, I position my loader bucket in full dump position and lowered to take the weight off the front wheels.
There have been times when I'm surprised how much "trouble" the hoe had removing a rock. One time it looked like I could just pick it up and pull it out myself...so I tried it. It wouldn't budge. It's amazing how much force is necessary to pop some of these things out of the ground.
I now just take my time, and realize that however long it takes to dig with the hoe, it'll be much faster than using a pick and shovel.
~Rick
