tungo

iTrader: (16)

It's not the wheels or tires. Don't know where to post, but I need some input on where to go from here.

The car is a 2013 GS F Sport with 9K miles. Lowered on BC Coilovers with 12K springs. Driving home in the rain and swerved to avoid a piece of debris, leading me to slide into a curb at 20-30 mph on the passenger side and felt a vibration. The wheels are not bent and tires were road forced balanced. Alignment is still straight and true. Car was taken into Lexus 2 weeks ago and they did an inspection and everything checked out. Brought it in again today to have them look at it. 3 technicians thought it was the wheels or tires, maybe both, but all checked out. Took another set of wheels off an F-Sport and put them on my car and same deal. The weird thing is that this vibration only occurs at 40-45 mph and 70-80 mph, which are essentially the speeds that I drive at all the time either on the street or highway which makes it worse for me. I took it up to 120 to see if I could replicate the vibration and it is as smooth as butter, except at those indicated speeds.

The one thing that annoys me the most in any car is a vibrating steering wheel now to the point that I have already heavily considered trading it in if I can't fix it. Car isn't even fun to drive anymore.

They have eliminated the wheels and tires as the culprit. My coilovers are fine. Technicians don't believe that I bent anything, but I really think that I did ever so slightly that we just can't see. No oil leaking from the axle and the boots are good. Now I'm thinking it could be a control arm, axle, wheel bearing (no noise), bushing, wheel hub, toe links or even something in the drive train such as a carrier bearing? I highly doubt its the drive train as I haven't heard any noises and the car is still relatively new. I'm not a technician, but I know enough to get by, yet this one stumps me. Suggestions?

mmarshall

I take it that this is not a buzz-type vibration in the steering wheel, but a regular back-and-forth shimmy at certain speeds, right?

A bent wheel hub can cause shimmy even when the wheel/tires are perfectly round and balanced.....but not always just in certain speed-ranges like you mention.

One thing you did not mention was tire-runout. Did the technicians do a runout-check on the tires? Slightly out-of-round tires can cause a shimmy even if perfectly balanced. Runout is checked with a gauge that looks somewhat like this, and should be checked on both the inner and outer edge of the rolling tire to take into account any lateral runout across the tire edge. You can sometimes tell the runout on a rolling tire with the naked eye if it is significant.



Last, something very important: when was the last time the shop calibrated its wheel-balance equipment? There's a old saying....garbage in, garbage out. Electronic wheel-balance equipment has to be periodically re-calibrated to be accurate.

Good Luck.

lobuxracer

iTrader: (2)

You slammed into a curb? I'd bet a whole lot of money you dented the wheel bearings. Not easy to diagnose without changing the hub assembly or assemblies depending on how many wheels hit the curb. It is best practice to replace either wheel bearings (if they are available separately) or hub assemblies when you curb a wheel hard.

mmarshall

I myself have never heard of bad bearings causing a shimmy (especially at varying speed-ranges). But, since you used to build race cars, I'll defer to your greater experience here.

lobuxracer

iTrader: (2)

You would hope, but the wife rented a Chrysler once and slammed into a curb in the rain hard enough to damage a few parts (she is used to premium rubber and rentals never have this). The hub was not bent (hard to imagine, but true), and the mechanic for the rental company changed out the hubs because his experience told him the wheel bearings would start having major issues in about 1500 miles. It is also possible the housing holding the wheel bearing is no longer round, and the bearing is moving around in the housing. That's why it is hard to troubleshoot. Unless you're able to generate equivalent forces on the wheel (impossible by manual manipulation) while it is in service, you'll be scratching your head and wondering WTF is wrong unless you've seen it before.

bitkahuna

iTrader: (20)

so if you tried a different set of rims and same problem, then it's not the rims/tires.

must be a damaged suspension component (rod, bar, spring, shock), or a brake mechanism component that got 'moved' / bent, or somehow the axle / wheel bearing / hub is damaged.

edit: i see the latter has been suggested now.

tungo

iTrader: (16)

The dealer working on it is Hendrick Lexus. The dealership moved to a new location just over a year ago and all of their equipment is new. Even have in-ground alignment rack.

I should have just driven straight and suffered the cosmetic damage instead of trying to avoid it. At least I would have known what was wrong in that case. Tires were balanced once hoping that would fix it and when it didn't, they were road forced twice, which showed no run out or out of round tires. It's not a shimmy in the wheel at all. It is a vibration in the steering wheel that is ever so slight, but enough that I can feel it in my forearm when my hand is on the wheel and only at the mentioned speeds. First thing that I mentioned to them after the tires were balanced was the wheel bearing, but because it's not causing noise, they eliminated that as the problem.

What's strange is that when I hit the curb and curbed the wheels, the front rim suffered very minor curb rash (5-6 inches), but the rubber lip protector of the tire was nearly ripped off all the way around, but the rear wheel which had curb rash on over half of the wheel (at least 12" of curb rash) did not suffer any damage to the tire at all.

Would you recommend I just order a full hub assembly for the front and rear? I'm willing to do it, as long as it's not in the $3-4K ballpark range. At first I thought it was me being nitpicky, but having access to 3 other cars and this loaner, it is definitely different. And my service advisor (top notch guy) gave me a hybrid for a loaner, which makes no noise at all. Didn't even realized the car was on when I started it. It is the quietest thing on 4 wheels that I have ever come across.

dmvp29

You should take the car into a dedicated collision repair center - not a simple dealership.

Lexus usually has a list of "certified" collision repair centers. You should ask your local dealership for that list or search google. They will know about the nuances of what lobuxracer and others have mentioned in this thread so far.

dmvp29

I made the same mistake with my honda civic many years ago. I hit a curb at 40 MPH and it changed the car for good. The steering always felt crooked when driving straight and there were odd vibrations at various speeds. I initially took it into the Honda dealership and they basically just said everything checked out and that I was crazy.

After months of fussing with them I finally decided to take the car into a collision repair center and they fixed the problem completely.

lobuxracer

iTrader: (2)

Yes, without hesitation.

Front hub is part number 43550-30050. Less than $400 from Internet Lexus retailers. Sewell pricing is $360.30 for CL members (FWD). AWD is considerably cheaper at $213.60.

Rear hub is part number 42410-30040. Less than $250 from Internet Lexus retailers. Sewell pricing is $229.79 for CL members.

tungo

iTrader: (16)

Thanks for the advice. A frame shop was my next stop if I can't sort it out at the dealer. Gonna have two different technicians look at it this weekend and keep the car for the weekend to see if they can figure it out and mention the wheel hub to them. It's so frustrating that I can't figure it out.

If that doesn't work, I will consider trading it in. I've invested a lot of money into the car already and would hate to do it, but trade-in is my last option. Every time I get into the car, I know the vibration is there and it takes all the enjoyment out of driving the car.

tungo

iTrader: (16)

Coincidentally, I was on Sewell's site looking for those parts right as you mentioned the numbers. Will wait to see what Lexus and their most picky technician according to my service advisor says about it and go from there.

I have a set of AG forged wheels ready to throw on, but really don't want to now that this happened until I find out what's going on.

lobuxracer

iTrader: (2)

I haven't had a good experience with dealer techs recognizing issues. We just went through a whole deal with IS-Fs making a weird random noise at idle. Replacing the serpentine belt and tensioner fixed it for me. Another member had his car at Lexus for two weeks while they tried to blame it on a host of other possible issues. They finally did what I suggested and the noise went away...be patient with them.

tungo

iTrader: (16)

Thanks for all of your suggestions. Patience isn't a problem considering the service that I've received. My service advisor Jacob is great and understands my frustration. Going above and beyond to try to figure out what the hell is causing it. Driving it himself. Setting the trip odometer to tell me how many miles he's traveled with the car. He's not just trying to get me in and out and isn't blaming my coilovers as the root cause (everyone knows it's not), like the majority of others that I would expect to because I went aftermarket on my suspension.

SlangBlade

Glad to hear the dealership is working with you, the same thing happened to my Integra and had to replace a bent wheel along with the sub frame. I also ended up getting rid of an Accord which had a shimmy that wouldn't go away, because I couldn't stand the vibration in the steering wheel. It drove me nuts to the point I didn't even want to drive the car (and Honda kept denying that there was a problem - another reason for my switch to Lexus).

Sounds like you're on the right track. I tend to think it's something that spins as opposed to a control arm or the like. You could always try replacing one hub at a time (I'd start with the front, even though it sounds like the rear took the brunt of the impact, because that's where the steering feel is).