Small Engines (Lawn Mowers, etc.): Snapper Rider {drive train}, snapper rider, output shaft

Question
Model # is 33131313be, Ser.# 45645115 I have no drive forward or reverse. what ive checked so far.The drive disc on crank is spinning. The driven disc is spinning.atleast when i move the driven disc by hand it is. The axle on both sides of the chain case are spinning, but wheels are not. Ive got two of these although different models so I set both upright and with the working mower when I spin the right rear wheel the driven disc spins but it does not on the one in question. Any help will be great. Thanks for helping all of us.

Answer
If the input shaft in the transmission is turning but the output shaft are not I would suspect the shift key inside the transmission to repair this you will need to remove the transmission open it up and thoroughly clean all the parts it is important to remember where each Bushing went so you can get it back the same place the shift key travel from right to left inside the gear when you take it apart you will find them on the output shaft.  Other than that I would suspect broken pull the key or just woren gears.  

You say that the chain to the transmission is turning if that is the case drive disc and driven disk should be okay.  The grease inside the transmission is made by Tecumseh it is recommended that you see a Tecumseh dealer and purchase that grease.

Good luck on your project