Hit a pretty steep pothole on the highway going at 115km/h on early Sunday morning (4:40am). Honest to God I didn't see this one coming so that was unfortunate on my end. I checked my tire pressures immediately from the gauge cluster and had to find a safe spot to park my car for a full inspection. Funny enough while I was worried, my car was still driving smoothly and I felt that my tires were still in good shape (I would instantly know if I really blew a tire as that has happened to me before).

When I checked beneath the vehicle, there was a scratch under my left skirt and my exhaust pipe (from the left side, since this is a true dual exhaust) hung lower than the usual. I thought it had been from the impact but when I tried to budge it, it seemed that the exhaust pipe was installed that way.

Today I went to the dealership and requested to get a full inspection (I'm pretty particular about servicing my Lexus only at a Lexus dealership, otherwise any other mods are usually done in other shops). They found that my front left control arm is SLIGHTLY BENT but the vehicle is still drivable. Left toe was off from the impact so I had to redo an alignment on that. My service advisor told me that it's not worth the replacement but eventually, if I do start to feel my car pull to the left or if my steering wheel is off from centre then I'll have to replace the left front control arm assembly (lower and upper) and also the knuckle.

So I left and drove the vehicle some more. Some things I noticed: steering wheel really isn't in the centre, it's off by 10 degrees to the left from the centre and I would have to keep it in that position while driving on the streets. On the highway, I was advised to drive in the centre lane (and I always do) and let go of the steering wheel and see if there's any pulling to either side. It's slight but not so prominent, I'll have to turn my wheel a bit but otherwise it's not so much of a hassle.

Here's my actual question: I have ordered RCF LCA bushings for the sake of improving front tire wear and while I wanted them installed, I also thought about replacing the slightly bent LCA assembly. Dealership recommended replacing all 4 on both sides and it's gonna run me a couple grand. Honestly, after getting my brakes done last week I'm not looking to get this done just yet. It's a lot of money to drop at the moment. What really worries me the most is that due to the front LCA being slightly bent, tire wear will be more pronounced. Should I replace that whole assembly? Or keep it on and just install the RCF bushings?

 

Sorry to hear this happened. Some of those potholes out there are pretty bad...I know, I've hit a couple myself.

Seems like a lot of parts they are recommending to replace, which makes me question it.

If they did an alignment, could you post the printout that they should have given you. That would help to determine if you really need all those parts.

 

Left front control arm assembly (lower and upper). Service advisor recommended replacing all four, sounded vague but I’m assuming both sides of the car. Also knuckle, is that steering knuckle?

 

Did they provide you the actual printout of the alignment? It should have been included with the workorder.
Realistically at this point there is no proof the alignment was done...I'm sure they did it, but I'm just saying that the printout would show you the before and after measurements so you can see what was out and what they adjusted.

I really doubt you need all those parts...and I really doubt the control arm is bent. The alignment printout would confirm both.
If the arm was bent enough the tech could see it with the naked eye, then there would be no point in doing the alignment as it would be way out and not correctable.
Maybe they can scan/email it to you if you didn't receive it.
To me (only my opinion)...they really don't know what needs to be replaced so they are recommending everything that could effect the alignment in the front.
Absolutely for sure if you throw all those parts at the car the alignment will be corrected, but do you really need all those parts.
And if you bent a steering knuckle the car would be effed when you're driving it...which clearly it isn't.

Assuming your car is AWD, you also have Camber adjusters in the front, so if the car was pulling slightly, it might be correctable with the adjusters.
Really without seeing the alignment printout, these are just my best guesses.

 

Nope, there was no printout of the alignment given to me. Your answer is starting to make me doubt going to the dealership to get this fixed, you clearly know more than these mechanics.

My IS is AWD. I still feel minor pulling to the right if I let go of the steering wheel on the center lane of the highway but that pretty much happens with every other vehicle I’ve driven. Unless something is off. Also, steering is still not 100% in the center.

would you say that the LCA isn’t really bent then? What would I need to get fixed, the camber adjusters at the front? I thought it was only the toe that got affected.

Apologies on the questions asked, I really don’t know too much about cars to this level. I know general camber and toe alignment in wheels and how they affect driving but when it comes to damage, that’s where I’m lost.

Anyways, I’m expecting to receive my RCF bushings sometime next week. I plan on getting them installed but at a different shop. Perhaps I could get a clear diagnosis at that shop then?

 

To be clear on my steering, it’s not a fight but I have to do mini 5-10 degree counter steers when driving straight on any road. My steering wheel would normally be straight but on a straight road, it’s turned to the left slightly by a couple degrees. Nothing too bothersome but it doesn’t help when I’m sort of OCD. Even on the highway. What’s really confusing me more is if I really have something damaged in the LCA assembly.

 

Yeah if it were me I'd listen and do exactly as he says lol. Starters get the alignment sheet from them before determining how to move forward. They should be able to email that over or have a print out waiting for you. Best of luck! (And that would be crazy if your LCA is bent but your tires and wheels were OK, doubtful).

 

Oh yeah. And I’m glad I’m getting better feedback compared to what my service advisor gave me.

My tires and rims are both in great shape, thankfully they weren’t shot. I just got new summer tires on them and I would’ve been devastated lol. Luckily I stuck with my factory F sport rims. They have seen plenty of extremely bad roads and still hold up pretty well!

 

1. Would you say that the LCA isn’t really bent then? My money is on it not being bent...but the alignment sheet will confirm. As @HOMER350 noted, the rim and tire are fine, so really what was the chance the only damage was done to the LCA.
2. What would I need to get fixed, the camber adjusters at the front? I thought it was only the toe that got affected. If the LCA was bent, then likely it will throw out the Camber, Caster, and Toe. Ideally replacing the arm will correct that along with an alignment.

The steering wheel not being straight is a product of the Toe not being set properly. The tech may have set the Toe even side to side on the front, but if the steering wheel wasn't straight when he did it, so then it won't be straight when you drive.
Basically the Toe needs to be adjusted again with the steering wheel straight.
Also we haven't even discussed the rear...assuming the left front wheel hit the pothole, I would assume the left rear did also.
Very likely the rear needs adjustment, which directly impacts the front alignment specs. Some techs will see the rear specs in the green and just move onto the front, but sometimes those tiny adjustments in the rear to make the specs dead on will have so much of an impact on the front.

Without the alignment sheet we are pretty much flying blind here...if they didn't print it out then it should be stored in the alignment machine (which is basically a PC). They can either print it out or at the very least send you a screenshot...or a pic of the screen with the readings on it.

 

As long as you have enough tie rod to compensate for the bent control arm, I'd follow dealer recommendation and leave the control arm alone. you must've hit that pot hole pretty hard to bend stamped steel front CA. that sucker's beefy. surprised the tie rod didn't bend.

install the RCF CABs and just get the car re-aligned. if you're in the green, you're in the green. The car does not know or care if the CA is bent. Lexus inspected it so it doesn't sound like it's bent enough to be a problem other than you needing a toe correction. no biggy.

 

The car is AWD...the LCA's are aluminum...they are beefy though.

 

I’m going to an alignment shop on my next day off, my dealership isn’t picking up. For now it’s not a super big deal but I’d like to get my steering in line.

 

Requested an alignment sheet from the dealership, please tell me what you think based on the results.

 

Based on the alignment printout there is nothing wrong with the front of the vehicle...you don't need control arms (lower or upper) or knuckles...you can't fix what's not broke.
If i had to nitpick, then I would say that the front Camber could be adjusted so that the difference side to side was less that 0.3 degrees...ideally equal...but even as is it's still ok.

The only issue I see is the right rear Camber.
The left rear Camber is almost dead center of the spec range, so no problem there.
The right rear is technically within spec, but with a 0.6 degree difference in Camber, this will make the rear of the vehicle pull to the left.
The subsequent effect of this is that the front of the vehicle will pull to the right....which I believe you mentioned in a previous post that you were having a slight pull to the right.
Since there is no factory adjustment for rear Camber, then I would assume something is off ever so slightly in the right rear corner.

Outside of this being covered by warranty, I would simply get a set of adjustable rear camber arms (i.e. SPC, Godspeed, Figs, Megan) and have the rear camber set equal.
Once that's done the front and rear Toe will need to be adjusted. The front Toe needs adjustment anyways since the steering if off center now.
After that, the car should be driving straight...barring any rim/tire issues.

 

Thank you so much for the Godspeed response! You have been super helpful.

question: is the rear camber kit really recommended? Funny to think that I hit the pothole on the left side of the vehicle but turns out, it’s the right side that’s off.

I thought about just adjusting the front toe to straighten the steering.