Okay, let me see if I can properly explain this and get some of your ideas:

When I drive over quick choppy bumps in pavement I get a rattle in the rear of the suspension, but only when the bump is on one side. When the bump is long and activates both rear wheels, like a speedbump or a large road crack I don't get the rattle.

The sound seems to be worse on the right side and I can't really figure it out. Has anyone had anything like this, anything specific I should look out for?

 

Not sure about the gx but sometimes brakes can rattle a little. Slightly press the brake and hit the same bumps and see if it goes away.

 

brakes dont rattle, they squeak when lining wears down

 

I respectfully disagree, brake pads can rattle, some vehicles have shims between the pads and calipers and as the pads wear the shims can start to rattle. I do not believe this is an issue on the GX but brakes can rattle.

 

Check your lug key and the other jack pieces behind the panel in the rear door.

 

Good idea! Will do

 

again, brakes should not rattle. when lining goes down, the piston squeezes the shims and pads closer to disc and keeps them tight. if they are rattling, you have a bad piston and it needs to be replaced.

in fact the shims are supposed to stop rattling, not cause it.
read here for yourself
http://auto.howstuffworks.com/auto-p...rake-shims.htm

 

The emergency brake needs adjustment.

Koz

 

Update:

Pulled out the entire piece that holds the lug key and all that stuff and its still happening. The rattle is definitely under the car, and happens near the middle of the rear suspension especially when the right rear wheel goes over a bump. One clue is that it seems worse in comfort mode than it does in sport mode (dunno if that helps)

I am due for an oil change soon so I will kill two birds with one stone, I will keep listening to it myself in the meantime. As is life, the tech who goes on the test drive won't be able to replicate it but I hope he will. Results to come!

 

yet another reason to avoid the AVS/air suspension. But it is a vehicle with a live Axel, which tend to squeak and rattle more anyway.

 

BEST thing to do it ask a Tech to ride with you and you demonstrate to him exactly what you are hearing!! dont rely on his 2 sec test drive after you leave the vehicle

 

Update?

Koz

 

the base version doesnt ride well, and the lx has the same system on all 4s, so your argument is bogus

 

No update, but its certainly getting worse. The rear end is a sloppy mess at this point, it sounds like a 15 year old F-150 that has been doing farm duty. I have an appointment booked for this week.

Edit: Spoke to the dealership, and booked an appointment for next Tuesday.

 

The base version rides quite fine. Also, the LX does not have KDSS which is a critical component so you can't compare the two chassis *****-nilly.

And knock off the condescending attitude, like your opinion is definitive or the only one that matters.