Thumping noise when braking

I have an '03 4x4 LS with 32k miles that started making a repetitive thumping noise while braking last week. When I brake hard there's no noise, it only occurs during light to moderate braking. It seems to drive and brake fine, I just can't figure out what the noise is and it's making me nervous. It seems to be coming from the front right. I've crawled underneath everywhere and don't see anything loose. I took the front right wheel off and everything looks normal. You can't really feel the thump, but it's loud enough to cause concern. Any ideas would be helpful before I decide to take it somewhere.

Welcome to AF, any work done in the front recently, make sure the caliper bolts and caliper bracket bolts are tight, you will not see this by just looking.

I checked the caliper and bracket bolts and made sure they were torqued to spec. Also checked the axleshafts and sway bar links and they're ok. Noise still persists though.

Only on site analysis will work at this point, obviously the wheel is tight and no witness marks on the inside of the wheel? There is no common issue reported on this condition, can you pinpoint when this started that relates to any occurence? Check Alldata.com for possible TSB info on this, I have a 2002 and though it has been very troublesome from day one, never had this issue. Did replace a ball joint and the usual links, but not this problelm.

Like Max says, you might need to get it up on a lift, or have a GM tech (not a mech for gawd sake.:uhoh: ) troubleshoot further. The only repeated front right issue I've heard of is a worn bearing carrier assemby on the inner end of the front rt half shaft. It's a sealed, grease filled aluminum bearing housing that's also used as the front axle disconnect.

Joel

Checked the brake rotors and pads? Sounds like rotors are warped. Very common issue on the TB.