I have a Craftsman lawn tractor with a manual 6 speed Peerless transaxle model 930-057A. It shifts normally until I have cut a few minutes and I guess the drive mechanism is warmed up, then I have to hit the shifter hard to make it change gears and sometimes that doesn't work. If I turn off the engine, then it will shift more easily but still not as easy as when cold. I suspected that the clutch pedal wasn't releasing completely and the drive belt was still moving, but I tested that repeatedly with my wife pressing the pedal so I could observe the belt and it is stopping. This is baffling to me. Has anyone had hard shifting problems with this type of transmission and successfully identified and corrected the problem?