TMaxxTim

I have a 2006 IS 350 with 206k, I'm trying to determine where this clunking is coming from. I've already replaced the rear sway bar links as recommended in some other threads. I purchased new rear sway bar bushines as well, but they did not fit tightly and since the original bushings were in solid shape I put those back on.

Clunking is only when hitting bump or a small curb for a driveway/shopping entrance/etc. It's only on the right rear, nothing clunks at all from the left rear.
Bare with me for this description, it sounds like a 2-step clunk, like there's a clunk when the suspension compresses and slightly higher pitched clunk as it releases the compression. I can faintly feel the clunk/pop in the seat of my pants when it does this.
It doesn't clunk over small bumps, everything seems smooth then and I haven't noticed anything different in the way the car drives.
I replaced the right rear wheel bearing (already replaced the other 3, this was the last one to do) and while in there tried to move everything around to find any play in the bushings or ball joints but it all seems rock solid.

I've seen some other threads where it could be a blown shock, or control arm bushings. I haven't ruled out any bushings in that area, but I didn't see anything that looked terrible or moved around too much when I was in there for the wheel bearing.

Any other ideas what to check or ways to check the control arm bushings that I may not know of.

I'm at the point where I may have to take it to my shop and have them diagnose since I'm at a loss as to what it could be and it's starting to make more sense to pay to have them diagnose it instead of throwing more parts at it.

Gville350

iTrader: (10)

Stock suspension?

Zmon

iTrader: (2)

I would think the obvious thing at this point would be to check the strut. Is the boot torn? Is it currently leaking (is there oily residue all over it?) How's the tire wear?

Aspect

if you've checked all suspension... how's the drive axle looking?

MikeFig82

iTrader: (13)

Like Zmon has said I would test the strut also. Open the rear passenger door. Have someone bounce in the seat, and see if you can reproduce the clunk. My old GS400 had a blow rear passenger strut. On smooth roads it was unnoticeable, but on even roads with dips. The thing had now absorption, and would bottom out hard, and clunk was felt in the seat too.

Mike_1GO

iTrader: (2)

could be a worn sway bar end link