Small Engines (Lawn Mowers, etc.): Mower front wheels are locked up, worm gear, self propelled mower

Question
I just bought a Craftsman 625 self-propelled mower. The front wheels do not turn, even when the mower is running and the drive control bar handle is engaged.

Answer
 Hello Dwight:

 Send me the Model Numbers Off the Mower, Please. With these Numbers I can Locate the Proper Manual and Better Assist you. Usually the Problem here is the Pinion/Worm Gear and the Ring Gear Are Binding in the Transmission or Teeth have Broken Off of One of the 2 and has Jammed the Transmission. On Some Models the Front wheels will Only Move if the Transmission is Working. Check the Transmission Drive Belt. Is the Belt Intact? The Model Numbers I am Seeking are the Sears Model Numbers. Example: 143.xxxxxx, 532.xxxxxx, ect. Thanks.

 Respectfully

 John