I saw the link. Once I added a little weight to the front truck and replaced the traction tires it pretty much went away. As for traction tire replacement. I didn't have any spares handy and couldn't locate my stash of MTH Steam traction tires so I used this and has seamed to work well so far.
http://www.globalindustrial.co...d5QD0UCSJhoCLEvw_wcB