This is a stock hl tiger with new gear boxes and no tensioners? If that is correct , check the gear box alinment, if on track is hanging lower than another and the links are the same on both sides, you might have a gear box angled forward or back and this could be causing the bunding or ristance. you should be able to lay a strait edge across the gear boxes and have both axils line up.......just a guess without seeing the tank...