Is the steering rack a common replacement item for a 180K 240? Been having a steering wheel shimmy from 50 mph on up. New Michelins and a rebalance have only made the problem worse than it was before, probably because the Michelin is a stiffer tire than the previous Toyos. Inner and outer tie rod ends have no play but there is noticeable radial play between the rack and the rack housing. My assumption is that the bushings between the rack and the rack housing are worn.