[maple_leaf_eh]

As a boy in the 70's I remember visiting a farm and the fellow used his farm tractor off road in the sugar bush. It had a front idler/tensioner axle mounted under the transmission. I think there was a roadwheel on the ground. The tracks were two heavy woven belts with curved U-channels bolted in between, and the tractor tires rode in the curve.

In the context of your 2 1/2 ton, a pair of tracks around the rear wheels wouldn't be much different - only much harder to tension.