I have an issue with my garage door. It is a 7ft x 16ft door with a torsion spring setup. Recently I installed a liftmaster 8500 jackshaft opener and found flaws in the door that didnt present themselves before. My issue is; The door appears to be pulling to the left when opening and not staying centered in the tracks. This is causing the left lift cable to rub on the track and the door to slightly bind about halfway through opening. It seems fine when closing. Ive gone through some of the basics, and cant seem to find a solution. Any advice would be great!..