Though not familiar with your exact machine, the answer probably lies inside the lower cover and will need inspection. bolt out of a jack shaft, broken carrier, spring etc.

OK, thanks Tom. I did remove the inspection cover from underneath and found all sorts of rubber material laying in the bottom along with metal shavings. A chunk of rubber got in the sprocket and cog for the rear drive shaft. I cleaned that out and now it rolls freely. I also found the blower drive belt is loose and slapping when disengaged after I removed the belt cover.

Back to the drive system, the vertical wheel is very loose and wobbles side to side so that much be shot. I get just a little forward motion from the drive system now even after adjusting the cable tighter. Seems I have multiple problems here.

It's not so bad once you have the cover off. It sounds as though that the friction disc came apart and created all kinds of issues. A significant amount of wobble isn't good. While you are there you want to know that the driven plate also seems secure. Look for lateral movement in bearing and such.