I have a Craftsman YS4500 Lawn Tractor. While I was out cutting the grass near the edge of the lawn, a vine in a bush snagged the gearshift lever pulling it back while the tractor continued foward. The tractor slowed, but did not stop. When I put the gearshift back into the regular grass cutting speed, the tractor traveled much faster than normal. When I went to park the tractor, I noticed that I had no reverse. In fact when the gearshift was in neutral, the tractor traveled foward as if in 1st or 2nd gear. When the gearshift is in reverse, the tractor is in neutral, that is, the wheels will spin freely. Any thoughts?

Thank you

Jim Liptack