Unless you've got bologna skin tires on it, i'm leaning more tward the dragging brake senerio someone mentioned.. my '46 2 ton will walk right up wet/snowy/muddy/sandy grassy hills with no problem at all.. and thats with weather checked, 40 year old tires on it.
If you put it in reverse and just let off the clutch (no touching the gas pedal) can you back up at idle?
