98 transmission problem

hi i recently bought a 98 camaro Z28 from my cousin, and well she drove it in the winter and one day it froze up i guess and she couldnt get it out of park so she jammed into into reverse. It is an automatic and now it drives in all forward gears but has no reverse, does anyone know what could have happened, and also if a different type of automatic transmission could be used with the LS1 engine?

thanks

Look up for a replacement on here it will be the cheapest way to replace it www.car-parts.com (http://www.car-parts.com) , Good luck

John