I just recently installed B6s along with some RS-R springs and KYB strut mounts and the suspension does not sound right. I'm getting a thump up front while going over uneven pavement, like if the strut mount was loose although they're torqued to spec. It's not metal to metal sound, wasn't present before replacing the struts and springs, and can be felt more so than heard.

I'm wondering if anyone has had bad experience with KYBs strut mounts. I've used them before on other vehicles and haven't had problems.

It sounds like either improper installation or a defective strut mount. Your old strut mounts were probaby fine and you only needed new mount bearings.

Did you be careful to get the springs seated properly and to align the new mounts in the proper holes during installation? Did you get it aligned afterward?

You really need to take them out and apart and inspect everything to get at the source of the noise.

Could be defective bearings. One of the KYBs failed on my Highlander after 3 years. There was a metal-on-metal noise when hitting bumps while turning, and you could actually feel and see the spring move like it was crunching in the mount. Heck, you could even feel it through the wheel of the car. The bearings exploded out everywhere when I took the strut apart to see what was wrong.

If not, could be that the strut mount is not seating properly in the strut.

These are three weeks old and not really hearing a grinding type of noise, nor any noise while turning.

Took a look around again today and I'm sure i found the culprit. Looks like the springs are binding up top for some reason. Noticed one of the springs is maybe 1/2" away from the stop where it sits, and wasn't able to adjust it because i rented the spring compressor when i installed them.

Another thing that i noticed that was concerning was the gap between the CV and the trans. It's obviously still in there too not leak and function, although it definitely doesn't look right to me.

Might just let the alignment shop mess with it.

These are brand new springs, so definitely binding.

Gap between CV and trans

The 2010 rx350 that we handed down to one of our college kids had to have the fronts struts replaced. They were the originals at 155k+ miles, and one of them was leaking. After reading this thread, and considering other factors like my 2 jobs, lack of access to "permanent" spring compressor, and short time for winter break, my spouse decided to take it to a independent Lexus tech that has good reviews as well as good word of mouth. After a couple of days I was able to finally inspect the work that was done and was disappointed to find that they used duralast loaded strut assemblies. The kid, who's been driving it mostly, doesn't notice any real change, more importantly it's not any worse. Maybe rides a little smoother. Except for maybe the dealer, it looks like many small independents are going to the quick struts type setup, at least around here.

Curious if anyone has any experience with the duralast struts? Heck, I could have done it in 4 hours if I wanted to just get a quick strut type setup. I've taken the cowl off before for spark plug change, that was the most annoying part but once that is done, struts are easy to get to. At least the ride seems to be okay according to the kid, just wondering how long these will last. Thanks for your time.

So from what I read I have 3 options for a RX350 FWD 2010
KYB, Bilstein B4 and B6, all of these I find on Rockauto.com
It is for my brothers car and he likes stiffer suspension. Does the B6 fit with no modification, and what is difference between B4 and B6?
I read a lot but just need some confirmation here. Thanks!

So on Rockauto I find the Bilstein B4 and B6, also the KYB - REAR shocks need to be replaced only.
Does the B6 require any modification to fit the RX350 2010 FWD. Also what is the difference between B4 and B6, my brother likes stiffer drive.
KYB vs B6 and B4?
Thanks

No modifications required for the B6. Fitment is the same for FWD and AWD cars. B6 = Stiff but still comfortable, B4 = Comfortable but still handles well. KYB = Similar to B4, but not as smooth, still a really good choice.

Thank you good sir. By the way I checked your DIY page and I'm Impressed how analytical everything is!

Remember when ordering Bilsteins:
​​​​​​
The Bilstein front struts that fit the RX are those from the 2008-2013 Highlander.
The Bilstein rear shocks that fit the RX are those from the 2014 -2019 Highlander.

B4 is the softer basic model ride.
B6 is the F-Sport stiffer better handling ride.

Curious what this should cost to replace both front strut assembly and sway bar links?
Unfortunately I am not handy enough nor do i have the time.

Got a quote from the Toyota dealer--$3400.
Firestone $1645.
this is on a 2010 Lexus RX 350 180k miles. Car has been great to me--but hard to drop that kind of coin on the car.

Thanks!

I wouldn't take it to Firestone, too many horror stories heard from them - scammers. Both quotes are unbelievably high, this whole job only took me about 4 hours for both fronts and rears. Find a good, trust-worthy local independent shop to do it, I wouldn't pay more than 500 in labour. Nothing is special or complicated about the suspension on this car. Source parts out yourself to avoid markup.

Those prices are insane. Where are you located?

That is way too much money for that job and I too would never trust a franchise repair shop such as Firestone, Goodyear, Aamco or Midas to do this work.

This link may help you find a good local independent car repair shop.
FYI the RX suspension is very similar to millions of other Toyota, Lexus and other Japanese vehicles. Every repair shop knows how to replace struts and shocks, they do it all the time.

The link is to shops recommended by listeners of the Car Talk radio show in which listeners called in for car repair advice. You can enter your city and state. Once you have some likely shops, cross check them on Google or Yelp for more current info as some of the reviews are a bit old.
https://www.cartalk.com/mechanics-files

Connecticut