I bought this at an auction, they said it ran but the fuel stop on the pump wasnt working. I fixed that little problem but the engine would not turn over, took starter out and bench tested it, it was good. Now I was worried engine was froze but luckily it turns freely. Now to the question, I decided to pull the tractor (pop start) to start it without the starter ( in 4th high selected) when I let the clutch out one rear tire turns backwards. Nothing seems bound up, even in gear with power director in neutral the tractor will roll just fine, or if I have clutch pushed in with it in any gear and power director engaged it rolls fine, could it be the engine has such good compression its causing the rear wheel to do this not allowing me to pop start it? My Series 3 Diesel doesnt do this, any suggestions? Also I pulled out the injectors to have less resistance with compression and the rear wheels did the same thing, moving in opposite directions, what would be the cause of this?