This sort of tool is very useful for isolating the source of knocks
and
While the genuine article is bit pricey per Mueller Kueps 432910 Suspension Wear Indicator Measuring Tool | eBay there are cheaper alternatives available e.g. SUSPENSION CHECKER CHECK TOOL TESTER PLAY IN YOUR SHOCKS BUSH BEARINGS | eBay I bought a pair that look the same as the Mueller Kueps ones for $50.00 for a few years ago but that brand no longer seems to be on ebay but this is probably OK Check Crowbar, Suspension Wear Tester Bar, High-special Steel, Black | eBay albeit more than twice what I paid. I find them invaluable. In any event don't overlook things like loose parts on the door (open the front doors and bounce them gently), loose upper coil-over mounts and loose rack mounts (get someone to watch the mounts while you swing the steering wheel back and forth), loose brake caliper bolts as well as the more obvious upper and lower ball joints, tie rod ends and anti-roll bar bushes.