Worn bearings and bushings are pretty much the number one maintenance issue on any vehicle with suspension. Best you can do is check for play in tie-rod ends, control arm bushings, ball joints, shock bushings, and wheel bearings. It could even be the bypass shocks are worn and need rebuilt. It may be best to unbolt one end of the shock absorbers to release any tension from the coil springs and let the suspension droop and see if things have play from wear & tear.
That's how I would do it with my quad when I was racing cross country. Bearings are a pain in the ***, but keeping the suspension and steering tight makes all the difference in the word as far as handling and ride quality are concerned. In off seasons I would tear the quad down to the bare frame and pretty much have to replace every ball bearing and bushing to keep things moving right and tight because competition beats the hell out of the machine , rider/ driver.