Before you lift the car, take off the wheel lug nuts, then prop it up on jackstands with wheels blocked at the opposite end. Take off the wheel and check the wheel bearings for problems or rust that's worse than expected. These bearings live inside a sealed metal cover that comes with built-in lubrication and can't be readjusted. Action: While lifting the car, spin the caster wheel unit, check for faulty noises, and look for bumps in the process. Carefully rotate the bearing while pushing or pulling it inside and out on its mounting points, also checking how it relates to the steering knuckle. You need to replace the entire part if you can detect any irregular sound or movement when checking the assembly.