vehicle thumps when hitting bumps dealer says i have a worn knucle.
how to replace rear driver side knucle on 2006 Lexus RX330
Wow interesting diagnosis! The knuckle wouldn't cause that. It doesn't really have anything to do with suspension and thumping and bumping. I would say from your description it sounds more like a shock that needs replacing or a coil spring (more like the rear shock/strut). This seems like a suspension issue not a knuckle. Only possibility from their diagnosis, is the bearing is totally destroyed and even then it is not the knuckle that needs replaced. Perhaps a mount broke off the knuckle? Take it to a local shop not the dealer and see what they have to say.