I've hit mine with a small impact a handful of times and never had an adjuster issue.

 

Are the struts bottoming out? Bump stops hitting?
When i first installed my coils i didnt adjust anything out of the box and the coils actually didnt appear to be spun to low, after i set the car on the ground the car was literally on the ground and was so low when i test drove it the front upper control arms were bottoming out into the fenders and the rear was hitting bump stops hard even on minor bumps.. After taking all of them back off i actually had to unlock the bottom collar and spin all the strut tubes out of their bodies quite a bit in order to get the clearence/adjustability i needed, i still have so much play room its not even funny..
Sorry if this is the stupid obv./newb explanation lol but sometimes ya never know. btw i have BC coils, LOVE them( guess im one of the lucky ones)

 

Joe, thanks for the suggestion but this isn't a case where the car is on the floor. I have about 1 finger gap between the tire and the fender.

The pre-load is set correctly and there is plenty of bump travel. I can go a lot lower in the rear without touching the preload too.

I'm leaning towards a lower mount issue or the shock itself having some sort of a problem.

 

AVS, have you looked into the carrier/knuckle bushings along with the trac-link bushings?

After reading the on-going thread below, I have a hunch that it could be related to those based on the symptoms.

https://www.clublexus.com/forums/sus...placement.html

 

I have literally replaced everything in the rear on mine - and it still rattles.

 

Got coilovers? Have you replaced the shock cartridge? Lower shock mount? Upper hats? Carrier bushings? Trac-Link Bushings? Sway Bay Bushings? Sway Bar Links?

 

Sorry, should clarify, everything except the HSD coil overs has been replaced, however they have been inspected bottom mount and shock has been inspected closely - all is well, is most likely the pillow ball top mount causing it, but haven't bothered to replace yet.

I have replaced subframe bushings, every single arm bush - upper and lower control arm, traction links, new toe links, new figs sway bar links, figs carrier bushes, diff mounts - rear and ears (uprated poly) and installed 6 link rear bracing.

Not Specifically to get rid of the noise - just part of my project, but in doing so I am pretty sure everything except the top mount has been eliminated.

 

AVS, I don't know if your problem is the same as mine, but I found the source of my problem today:

https://www.clublexus.com/forums/7854950-post252.html

 

hm....... I might have to get my mechanic to look it up. but no one in NA has that bushing available?

 

Ya, it's odd. For stock style replacement carrier/knuckle bushings, the only places we know of are Ireland (ebay) or New Zealand for stock style.

FIGS also carriers a redesigned type.

If you want to get the parts here in North America, you have to buy the whole assembly from Lexus... Not cheap.