I have a sears 1000 riding mower (purchased in 2001). It has been pretty faithful. I used it a week ago and this week after starting it, the gears don't engage. I can ut the lever into reverse, neutral or any of the forward gears but nothing happens. Has anyone had this happen? Do you know what the problem and solution might be?

Check the linkage between the handle you touch and the transaxle under the seat, one lost cotter pin can cause this to fail. Also, check the big pulley on the transaxle, if a key is broken it can spin freely.

The belt could be broken or it has slipped off the back pulley. My Craftsman used to throw the belt all the time.