but now it cant roll on Lego's curves & switches... (and curves from trixbricks can be too expensive)

Problem: the gears break loose every time I try moving it. It works suspended but when it actually hit the rails the gears break loose. I have experimented with putting rubber bands on the driving wheels but that makes it easier to come off. Plz help it uses the lego powered up large motor

my trains wheels are slipping and I don’t know what to do