Craftsman front wheel drive mower won't drive.

[Pete E. Kruzer]

It has a gearbox that is powered by a belt from the engine. It doesn't appear that the belt is slipping. And the arm that engages the gears moves. Yet there's no power to the wheels. Well, I take that back. On a level driveway, it will pull itself along at a slow pace. At the gear box which is part of the axle "jumps up and down." And with the engine off and the gearbox engaged, the front wheels are locked as if everything is engaged. Any ideas on what the problem is?

[M.Paul]

My craftsman has the same setup and had the same symptoms. Turned out that the shaft (axle) that the gearbox drives had snapped in half. They must be fairly weak because I was just mowing the lawn when it broke - mower never abused. New axle shaft was about $30. PITA to replace, but it's been working great ever since.