I am very interested in knowing how rippers could be attached to my father's D4 7U (SN 7U40918) and where they might be found. The hydraulics are there, but it came with a drawbar. This tractor has more power than traction, so tracks spin when the blade cuts in or when trying to push more than loose soil, but I think it might pull a couple of rippers about 1 foot deep. It is now a ranch tractor, and rippers would help with moving dirt and getting grass roots to penetrate soil compacted by many years of grazing.