Clunk noise driving me nuts!!

[baddohtentahoe]

ok so its really getting to me now. its a 2010 4wd LT. going over big bumps at slow speeds (mostly speed bumps 5-10mph) im getting a loud clunk like something is loose in the front suspension. sounds like bad struts but they are not leaking and my tires are not cupped. basically when the wheels are at the top of the bump and returning downward or on the far side of the bump and the suspension is not compressed or is letting the strut extend i hear this thud or clunk noise. i did a quick visual under the truck, everything seems tight (bearings tie rods ball joints axles struts and sway bar) it really sounds like a bad sway bar bushing but i checked them with the truck on the ground and theres no movement. im stumped. could it be the drive shaft? steering shaft? its definitely coming from the front so i dont know. im open to suggestions. ps STOCK SUSPENSION STOCK 20s

 

[Modded]

May be that the front crossmember has come loose.

 

[baddohtentahoe]

i did read about that on the gm trucks forum. im going to get it up on the lift and check it out. im assuming if it is moving it will show spots on the factory undercoat around the bolts where it has been smoothed over by the bolt. is there a TSB for that?

 

[Modded]

Yeah there is a TSB on it but I don't know the number.

 

[baddohtentahoe]

by google i can only find that tsb for nbs trucks not nnbs i wonder if it applys to the nnbs

 

[GM Customer Service]

baddohtentahoe,

Can you feel it in the steering wheel?

Louis
GM Customer Service

 

[baddohtentahoe]

no it does not feel like a steering issue. no difference or looseness in the steering wheel and i did check the tierods. theyre good. it sounds like a bad strut or bad sway bar bushing but when i checked the sway bar bushings they were still tight(suspension loaded on the ground) and the struts are not leaking or cupping the tires. im lost about to take it in to the dealer