Craftsman LT1000 mower won't drive straight and wheels point in dif directions

I began sharing neighbor's mower about 2 years ago. I look after it mechanically (just the basics -oil changes, blade changes, belts) and he lets me use it. Good deal. Until recently, when either my son (age 12, who has started mowing for me and generally very conscientious but confesses he lightly bumped the car tire a week ago, no damage to the car or tire so I believe it was at very low speed) or the neighbor must have hit something or forced the steering in some way. The mower will not track straight. If I let go of steering, it turns left and cuts a 20' circular path or so. Even with holding the steering hard, the location of the steering wheel has changed quite a bit, about a 90 degree (1/4 turn) rotation in order to continue going straight. The front wheels also seem cambered inward at the top when resting on the ground and don't don't quite point the same way on the ground or when the front is lifted off the ground.
Found this site via Google and read thru several threads but didn't come across these symptoms. I am a learner and a fixit by birth and necessity but confess that motors and linkages etc are not my strongest areas. My son and I will, of course, be doing these repairs TOGETHER so I would like to model good troubleshooting. Neither neighbor nor I have a Manual on this mower. It is a craftsman LT1000, green but I know little else other than neighbor is rough on it. Any docs and suggestions/directions to check/proceed to determine what is going on would be greatly appreciated!

 

There is a bar that runs underneath the engine and it connects one wheel to the other. It is supposed to be straight, but yours is not. It got bent. Take it off and bend it back straight and your problem will be solved.