OldLs400

My mechanic noted a lot of feathering on both sides of my front tires. These are good tires with a fairly high treadwear rating of 500 or so. These are Continential Control Contact Sport tires. I have about 15k miles on the tires.

I've read a fair bit about the 2IS and its problem with uneven front tire wear. I've seen stiffer bushings being recommended all the time to help with tire wear.


As I've racked up the miles on my 2IS, I've noticed something very interesting: the vehicle sometimes pulls to one side during heavy braking. It wasn't the alignment, as I have the vehicle aligned very often and even got the alignment checked. It's not the brakes--those were checked and are perfectly fine.

This is my train of thought:

• The soft LCA bushings create the dynamic toe out as shown in the picture above, leading to abnormal tire wear on the edges.
• My car has 130k miles on it, and the LCA bushings are still original. So they're probably even softer than stock now, and this has led to both tire wear and the pulling sensation while braking--maybe one LCA bushing is softer than the other now and this creates an imbalanced feel while braking.

Does this make sense?

If so, what's the best bushing I can buy? RR-Racing bushings? Figs? Stock IS-F/GS-F? Something else I haven't thought of? I have a 2012 IS350c, if someone could point me in the direction of some part numbers for stiffer bushings to help with front tire feathering, that would be highly appreciated . Things I would be concerned about in a new bushing would be:

• NVH increase--how bad is the NVH increase from the Figs/RR racing and other stiffer bushings?
• Squeaking and maintenance--I read that the high-performance aftermarket bushings can squeak and need periodic lubrication? I'd hate to crawl under the car often to lube the bushings. Are the stock Lexus IS-F/GS-F bushings better in this regard?
• How easy is this job to DIY?
• Do the aftermarket (Figs/RR racing) bushings do a better job of curing front tire wear than the stock Lexus IS-F/GS-F bushings?

Thanks in advance .


Edited to add:

I came across these part numbers for some RC-F bushings:

• 48075-24010
• 48076-24010

Could someone confirm fitment on a 2012 IS350C?

AMIRZA786

Use RR Racing Polyurethane (or Figs engineering) LCA Bushings if you want stiffer steering and more road feel, or RC-F bushings for a compromise. See my thread on this which has more explanation and part numbers, which will fit your model

OldLs400

Thanks for that thread. I liked your upgrades. I already have the sway bars and those are awesome.

I was thinking about the PS ECU but never got around to it.

Question about the RC-F bushings: which offset did you get? I see people suggesting just to get the 0 offset version.

Also, do you know about how many more miles you get out the tires after the bushing change? I've done some additional reading on CL and found that 15k miles for the tires on a IS is pretty good, all things considered, and that the first thing anyone should do in case of edge wear is increase tire pressure.

Finally, any thoughts on how my current tires look? I've attached an image of my old (15k mile) Conti Control Contact along with images of a new Conti Control Contact. I don't see cords (thank goodness) but that inner treadblock is half-missing. Would you say that the old Conti's are safe to drive on still, and for how long? The shop didn't seem overly concerned about my tires and didn't try selling me new tires, so I really don't know. I know seeing cords = bad.

AMIRZA786

I can't really speak in regards of the RC-F bushings except that they are way cheaper, and stiffer than the stock bushings. Also they don't need servicing like the Polyurethane bushings (they have to be re-greased every few years as they start squeaking). But I can give you more information on the RR Racing LCA bushings, which I have. Please see this thread:F-Sport Sway bar & LCA bushings discussion: https://www.clublexus.com/forums/is-...-question.html

As far as the ISF steering ECU, you can check out this pretty extensive thread: ISF Steering ecu discussion: https://www.clublexus.com/forums/is...oughts-on-installing-an-isf-steering-ecu.html

Your question about the tire life after changing the bushings, well I am about to find out! I bought my car last September 2019 at 52K. It needed new tires and brakes, so I installed Michelin Pilots AS. I drove almost 10K on the stock bushings, and front tires are fine right now. I changed to the performance bushings a couple of months ago, so we will see! I can't really tell you if your current tires are safe, someone more knowledgeable can way in. I would say rotate them and drive them to the ground before changing them

2013FSport

iTrader: (2)

Don't worry about the offset, just buy the zero ones. Do a where used on the OEM LCA for your C and if it takes the same bushing as the base, you are good. That said, I'm 99.98% certain the RCF LCA will fit just fine.

Also, don't hesitate to run the front pressure to 38 - 40 psi. It will save the edges. Then about 500 mi after LCA install, verify toe is correct for your driving style and usage. Just because the spec says one thing AND its set to spec, styles and habits vary, so one MUST tweak the toe for how the vehicle is used.

AMIRZA786

I wanted to make another comment on the RR Racing Polyurethane bushings. You'll see some posts saying they squeak and make some noise, especially in colder weather. It is true that because they are a stiffer material they will introduce some additional NVH, and in freezing temps the silicone grease freeze (it resists freezing down to -28F). In my case two weeks after the install I began to hear a rattling/squeaking sound going over bumps, up driveways, backing up etc. It was pretty annoying, most people were pointing to the RR Racing LCA bushings. I had my mechanic look at them, re-torque them and even reinstall them. I contacted RR Racing support and they told me that they don't think it's their bushings, and my mechanic felt the same. After some troubleshooting, it was determined that the cause of the issue was Sway bar End Links. At the same time I had also installed F-Sport Sway bars, and the added stiffness of both the sway bars and the stiffer LCA bushings put a lot of stress on the already worn End Links. New OEM End Links fixed the issue, a month later and no rattling or squeaking sounds! I bet this would be case for some members who experienced squeaking sounds they reported.

Going Polyurethane for the LCA bushings has it's tradeoffs. They are more expensive. They definitely make the front end stiffer so you feel the imperfections driving on a bad road. They need to be regreased every few years under normal use and yearly if you track the car. They do have the potential to squeak in colder weather. The benefits are stiffer and more confident steering in corners, better road feel (the front communicates much better), and my favorite...confident braking at high speeds. The steering wheel stays straight, you don't feel any wobble. And lastly inner wheel wear is reduced drastically.

RCF LCA bushings are the compromise. They are cheaper (a set is roughly $100, RR Racings bushings are $300 plus), stiffer than the stock bushings, and don't need to be serviced (regreased). They don't introduce as much NVH, but you don't get as much road feel and feedback (some people are prefer that). I've never driven on them, but I'm probably guessing they give you that Mercedes feel where you get some feedback, steering is confident, but you are mostly protected from imperfections in the road. TBH, I probably would have gone the RCF LCA bushing route if I had known at the time they fit the IS350 because they are a lot cheaper. That being said, I'm totally happy with the RR Racing bushings. So far they are pretty awesome. Lets see how they are a couple of years from now

jizz4jazz

iTrader: (1)

I recently installed RCF LCA bushings, they are a lot firmer than stock, noticeable difference. Everything feels tighter.

Aspect

I have the FIGS LCA bushing and it's been great. On a related note, whichever bushing you choose to upgrade to, make sure to zero the toe alignment else you'll still get the inner edge wear. Redspencer caught my mistake when I was still experiencing edge wear after I installed my FIGS LCA bushing

AMIRZA786

It's also recommended to get alignment done. Alignment was slightly off after installing the upgraded LCA bushings. I'm assuming the zero toe alignment you are referring to is done when you get your alignment done

2013FSport

iTrader: (2)

That's where you have to be careful. A good alignment tech will ask if hardware was replaced. A good tech will also ask if you have wear issues and if so, where if the car has new tires.

A less favorable tech will straighten the wheel, get the toe to spec and send it out the door. If they know certain cars have a specific behavior, they'll favor the setting towards compensation.

That said, driving use and style matter. As does tire pressure. I'm on an OEM stagger so rotating is not an option and to mitigate wear the fronts are at 38 PSI and the rears at 33. The rears blow the centers at 36 and the front feathers both edges at 34. And if they continue to feather up front I'll bump them to 40. Its all about managing and paying attention. A zero tow is best but doesn't work for everyone. Some will need toed in to minimize wear. A zero is a good baseline and adjust as needed from there....

OldLs400

How many more miles are you getting from your front tires now?

And by compensating for the quirks of the 2IS' suspension setup: should I ask my mechanic for less toe out when setting the alignment?

2013FSport

iTrader: (2)

I shove mine into the corners pretty hard and didn't apply what I knew soon enough when I saw inner AND outer edge feathering. That said, 40K on the fronts. 32k on the rear.

Toe-in = outer edge wear. Use this to compensate for inner wear.
Toe-Out = inner edge wear. Our 2IS does not want toe-out.
Toe-out in the rear makes a foul driving machine as it will try to drive the rear out of the ruts. Highly unfavorable.

Baseline everything at zero. Adjust pressure to get even wear across the WHOLE tire. If wearing on the inside, toe it in.

OldLs400

Holy smokes! 40k on the fronts and 32k on the rear...that's awesome! Wish I got that sort of mileage out of my tires...would have saved me probably a thousand dollars or more by now!

My Michelin Pilot Sports AS3+'s on the rear were easily down to wear bars after just 15k miles or so, maybe even less (I tossed the receipts). Then again, I probably take off way too hard at red lights. They had a funny wear pattern with more wear in the center than the edges. I will take your advice to inflate the rears some more. I stuck with the inflation specs on the door placard (35 front/38 rear), which, retrospectively, appear to be low.

I just need to find a reputable shop that will help me replace the LCA #2 bushings right now. I have one quote from a shop that couldn't find a book time, so they quoted "likely" $600. No way I'm paying someone to go on a fishing expedition for a LCA #2 bushing install. It's just 2 bolts. A bit of an oversimplification, yes, I realize that. I could conceivably do it myself, I guess, but $600 seems a bit high.

AMIRZA786

$600 is highway robbery! My mechanic, which is a well established independent shop did it for $200. Actually, he did the F-Sport Sway bars (front and back) as well as the LCA bushing! It's actually more than 2 bolts (I think 6 bolts on each side), and he had to use a breaker bar (the bolts were seized) as well as a pry bar. It took him a good 2 1/2 hours

2013FSport

iTrader: (2)

No NO NO....
Do not jack up the rear PSI.
I'm running:
38 PSI Front
33 PSI Rear

The fronts will likely go to 40 PSI for 5000 miles to minimize both edges wearing as I asked tire store to set it to 38 and found them at 32... sigh.

So, I run around empty all the time with just me and the car w fuel. Because the rears spin on occasion, and there's no load back there, the centers get blown from over inflation by running at the door plate settings.

But, that's just me and what I do....