Plower,
I don't know about the JD but my 'bota has 4 different ways to mount the rear tires. You pick up about 2 inches with each "change". I just finished putting them to the widest setting and it made a world of difference with hill stability. My tires aren't loaded and I did it myself, pretty easy. Take a look at how the outer rim attaches to the inner rim, thats the lugs you change, not where the inner rim attaches to the axel, that stays put. (assuming you also have two piece rims) It would also make a big difference on your lower link arms rubbing the tires.