Small Engines (Lawn Mowers, etc.): John Deere rx75, john deere rx75, transaxle

Question
While cutting grass the mower began to jerk as if a belt was slipping regularly or a tooth on a gear in the transaxle broke. Mower moves perfectly in reverse. At higher speeds it jerks at a faster rate.

Answer
Check your belts, but you may have hit the nail on the head with a broken gear.  Your reverse works off another gear.  Get is resolved soon because if you dont, that broken gear piece is going to get wedged between other gears and the case and cause major damage