Hi There,
I agree with everything in the first posting. "Brut force" is the last tool you should use to cure a problem such as this. You are lucky the engine doesn't have enough power or the clutch is too far gone to force the issue any further than stalling out the engine or a failure to move.
Your situation brings to mind a statement in one of Tuckers operators manuals, which reminded operators that although the machine resembled a light truck in appearance and construction, it needed to be operated, serviced, and cared for more as an airplane than a truck. The tracks roll around pontoons constructed of sheet metal or fiberglass. When something goes wrong, more than the track assemblies take the beating. The sprockets aren't all that robust either. When you get these freed up they should, and some would say must roll with a smooth even sound and no binding. This machine will never be all that quiet, but if you do it right it will be a blast to drive. Half done track work invites break downs. Remember you are working on a machine some consider to be the best at what it was designed to do. When you break down there probably isn't anything in the neighborhood that can come pull you home. Cheap, fast, and good. You can have any two, but almost never all three in repair work. I'd forget fast, and put time on your side. First I'd build a track "bathtub", plywood bottom with 2X4 sides and a drain in one end. Place it up on sawhorses so you aren't bending over all the time. You will be doing enough of that anyway. Line it with plastic sheeting and fill it with the best solvent mix you can afford. Cover the tracks and go find something else that needs attention for a few days. Drain the solvent and save it for the next track. Personally I'd stay away from excessive use of heat, unless recommended by others. As far as a penetrant goes, the best one I've ever used is "PB Blaster", but again time is needed for these to really do their best job. You might spray some cans of this stuff on a day or two before the soak in the tub. If things are really tight, and it sounds like they are, I'd give parafin wax a try, but you must use due care as it is flammable when liquified. Apply gentle heat to the frozen parts with a torch until you can melt the parafin by pressing the solid wax to the heated parts or you can brush on liquified wax to preheated parts. Be Careful, if overheated this wax will burst into flame. I use this as a last resort and have seen wax creep into spaces other penetrants fail to reach. Don't be scared off by this job. Anyone who has ever owned one of these machines can testify as to the amount of care they require. As you work on them remember how the tracks got this way. This is not a machine to be ever left in the dirt. Lubrication is a must. When you get to driving your machine listen to it. When something doesn't sound right find out why. Walking home in the dark or even with a good flashlight is no fun.
