Right after installing USRS bushing, this notchy feeling went away on me. Going home on a 2-hour drive while it's raining so bad and cruising ~85mph in NJ turnpike, car drives straight like an arrow.

Just sharing my experience and +1 to RR-Racing USRS bushing.

 

Interesting. So I wonder if the notchiness is partially due to excessive bushing deflection. All I can say is, it's not an issue for me in daily driving, since I don't ever go that fast (nor do I usually drive on the highway for that long). This was the first time I noticed it in 3 years of ownership.

 

Rcf/GSF bushings will do the same thing.
i installed them the week I got the car. The car use to pull and move on hard brakes, acceleration & any bend in the road the car would follow. Installed the GSF bushings and everyone of those problems was eliminated.
Tire wear issue fixed also. Parts were cheap to, with labor only cost me around $180 for everything.

Plus their OEM Lexus parts so no need to worry about voiding suspension warranty.

 

I hate to say that I had the RCF/GSF bushings for 10 months and I can't stress it out more, especially on a sudden hard braking, the car wants to go to the other side of the lane - thought it was my alignment, but it was not.

Again, not promoting, but the USRS eliminated all of these. I'm looking forward to the famous squeak issue though hasn't happen yet.

 

Really? I’ve had them on for 12 months and 25,000km and my car wandered so bad before I was convinced my alignment or suspension was messed up. I have zero wandering now under all situations. What year is your car?

 

2017 AWD

Still got them just in case USRS squeak issue appears.

 

I also experienced that problem several times and always it was about prolonged highway driving on highways that have very minimal or very smooth long bends. Notchiness is symmetrical and does not depend on the direction of where I was trying to turn the steering wheel to.
I also noticed that it goes away for a while, if I controllably, but aggressively quickly wiggle the steering wheel left to right several times (while driving).

My car does NOT have any LDA installed, yet I still experience this issue.

I have a feeling it is a firmware problem, and not just the bushings being too soft.

 

hm I’m pretty sure 2017+ IS’s had some sort of suspension revamping, I wonder if that’s why the results were less noticeable than me...I’ve got a 2015 350.

 

IS300 got no AVS so that might help too. Not sure if it's enabled on all modes, or just on Sport+ only.

 

arentz07 does not have AVS in his IS300, but my IS350 is Fsport RWD, so it does come with AVS. Both experience steering wheel notchiness.

 

But you mentioned it's already been resolved by installing the RCF/GSF bushings, correct? Coz mine didn't, but, I drive like a maniac.

Whenever I get a chance, I always turn an empty road to a track.

 

Did not mean to confuse you. I am not the OP, but the third “complainer” here, lol. I have not installed RCF bushings yets

 

Yes, my apologies. Hopefully your car doesn't need to have the steering gear rack replaced.

 

If the issue can be temporarily fixed by messing with the steering wheel, I am skeptical that the entire steering rack is no good. This feels more like a software issue if it can be "tricked" back to normal by the user.

I think it's worth noting, too, that both sunamer and myself have only experienced it on longer highway drives on straight roads. If it were something mechanical, I'd expect it to be noticeable even on shorter trips.

 

No worries, you are good.
But if it does need replacing, I wonder if I could replace it with the VGRS module instead....