Small Engines (Lawn Mowers, etc.): repair for Craftsman lawn tractor, craftsman lawn tractor, puley

Question
Last weekend my husband did something that punctured a tire and severed the drive belt. I got the tire repaired and a new drive belt put on (finally)but the tractor does not move forward.  It is a simple to operate mower. A foot break on the right and gear stick that is neutral, reverse or 1,2,3,4,5.  No clutch. Why won't it go forward?  It starts right up, I've checked the belt several times it's tight and on all the right gears and inside of required guards but no going forward.  Moving the gear in reverse or in forward does not seem to engage the engine (transmission?).  What's wrong?  What do I try next.  The mower is two years old model 9.17273632.

I'm no mechanic so explain things simply please.

Answer
 Hello Nancy:

 Go to this Addy http://www3.sears.com/ and Click on the Lawn Equipment Box. Follow the Instruction to get to the View Part Diagram Page. Select the View Diagram for Ground Drive. Check All the Linkage from the Shifter to the Top of the Transaxle. Use the Breakdown to Verify the Linkage Involved. When the Belt Broke, It May have Knocked the Linkage Off or Damaged it. If the Linkage is Ok, then Remove the Transaxle Drive Belt from the Transaxle Pulley. Turn the Pulley by Hand and Look at the Shaft. Is the Shaft Turning with the Puley? If No, the Key that Locks the Shaft to the Pulley has Sheared. Be Sure to Check the Shift Plate that Bolts to the Shift Shaft of the Transaxle as it May be Slipping on the Shifter Shaft. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John