Treadmill help or Suggestions

momtozmc

I have an older treadmill whose belt keeps slipping to the left...

Any of you know how to stop the belt on my treadmill from moving to the far left? I've adjusted it a bunch of times... but as soon as the belt gets going... it slips right on over to the left... even with tightening.... so much so now, that the sides are shredded... it is old but the motor is still good... suggestions?

New one? If yes, what are your suggestions under $600? Proform or NordicTrack?

Thanks
L