s80 will not move when its in reverese
 

please help. i changed my front two tires.i drove car into garage just fine.jacked car up seitched tires set it back down tried to reverse out . of garage and felt like it had a block behind wheel.wouldn't go. check E brake jacked rearend up tires rotate fine front rotate fine.pit it back down on ground put it in nuetral and it wont move then either