Small Engines (Lawn Mowers, etc.): Blade wont engage anymore, mower blade, mandral

Question
My dad purchased a Murray riding lawn mower 2 years ago (Model 309007x8A).  A few months ago, he went over a large ant hill that caused problems for the mower.  After this incident, the mower blade was damaged (bent) and the belt broke.  He replaced the blade and belt.  He still cannot use the mower because he can't engage the blade.  He doesn't want to force it to engage...Previously, the blade would engage very easily.  Could you please help us figure out what the problem might be?

Answer
 Hello Anthony:

 If The Belt is Routed Properly and the Blade Brake is Working Properly, then The Spindle/Quill Assembly Shaft is Most Likely Bent Also. With the Blade Brake and the Belt Off the Deck; Turn the Blade by Hand. If the Blade is Hard to Turn, then the Spindle/Quill/Mandral needs to be Replaced. Hope this Helps.

 Good Luck

 Respectfully

 John