I hear a random knocking in the front suspension, a clunk when the brakes are applied, and I see the rubber boot is missing from the drivers side lower ball joint.

What can I do to determine if the ball joint is suspect? Something like jack up the front end and see if there is top to bottom "slop" in the wheel?

Thanks.

 

Well if the dust boot is gone, so will the ball joints lube & moisture & grit can get in there & do dastardly deeds.

You can raise the front end on stands & use a jack, or rig a pry bar with a 2X4 or something that'll raise the tire while you view the ball joint area. It shouldn't have any visable play.

Grnding noise when turning, or maybe clunking when going over bumps, uneaven tire wear, vehicle not wanting to steer a straight line on a road with a high crown, or maybe it wanting to wonder in a cross wind & of course play in the BJ when unloaded, are some signs that they need changing.

My dust boots were cracked at 60K miles & the BJ's made a popping noise when turned well off center & when raised they had easily seen unloaded play.

I had both upper & lower "A" arm BJ's replaced on both sides, on my 4X2, as the upper dust boots were cracked too, along with an realignment, then put new Michelin LTX M&S on it last fall.

If your BJ's are so badly worn that they're clunking, don't wait to replace them as it's not safe if they're that worn.