Small Engines (Lawn Mowers, etc.): bolens rider mower jerking, transaxle, rear end

Question
what would cause a bolens 15 hp 38cut rider to jerk as you move forward but not reverse
It fells like it is in the rear end/trans.
I cant find any model number or manuals
please help

Answer
 Hello Dan:

 Bolens is Manfactured by MTD. Not knowing the Model I will Say if this is a Transaxle that a Tooth is Broken inside the Transaxle. Look on the Transaxle Housing for a Manfacturers Tag and Send me those Numbers, Please. I can View a Breakdown of the Transaxle and Better Assist you. Sooner or Later you will need the Model Number Off of the Mower to Purchase Parts. Thanks.

 Respectfully

 John