There are several things that can be causing this. Check the rubber tired driven wheel on the transaxle. Is it worn down, chunked out. Does it seem to have good pressure between it and the metal drive disc on the engine crankshaft.

You may need to loosen the gear shaft bracket, what the gear shift lever runs in, two studs, slide the bracket slightly forward, retighten and see if that helps.

The "Shifter Yoke" may be worn out. I'll see if I have a picture of that if need be.

Walt Conner

The rubber tired wheel, below the round aluminum disc on the bottom of the crankshaft, is easily replaced. I think there are maybe 3 bolts holding it on, and nothing else has to be removed. Last one i bought was around fifteen bucks, but that was 5-6 years ago. A twenty minute job of installing it. One thing when driving it, do not drive in the rain, or get water on the disc. It doesn't like getting its feet wet!