I have a Bolen's 1220 which I bought 20 years ago as a used tractor. The transaxle which has the high and low range in it is completely worn out and needs replacing. I have another tube frame unit that I acquired some time ago, which is in much better shape and has the high and low range. Everything I can look at and measure from the outside looks the same. Question One: Were all of those units in the tube frames the same? Question Two: How do you get the units off of their frames to make the change? I took the clamps off of the good one and hung it from my chain hoist from the front axle. It did not fall out. I tapped on it gently with a hammer, still no movement. Is there something else I to take off? Thank you.