SCWells72

I've had a vibration in my GS430 at about 65-75 mph since late last year. The vibration is most clearly felt through the steering wheel, but is significant enough that I can actually see the passenger seat headrest quickly oscillating back and forth as well as the seat back. It's most pronounced when I'm alone in the car. With a passenger it seems significantly better, perhaps due to the weight distribution (I'm a pretty average sized guy...6'1", 190 or so; it's not like the car's leaning heavily to the left because of me).

When I first brought the vibration up to the Lexus service guys, I was told I needed new tires (and I did), so I had a new set of rubber thrown on by the boys at Goodyear. Of course, that involved balancing and alignment, so I assumed the problem would be gone. Unfortunately after a couple of weeks, it came right back. I took the car into Goodyear and they did another alignment (for which I was charged) and a rotation and balancing (for which I wasn't charged). Felt good for about a week, then boom...back. I called Goodyear and chatted about it, but since I had my 25K servicing coming up at that point, I thought I'd go ahead and let Lexus look at my L-Tuned suspension, rims for bends, etc., before bugging Goodyear again. The Lexus techs went to balance the tires and noticed that at least one was out of round, so I took the car BACK to Goodyear and had them replace (actually two) out of round tires (free of charge). That was two weeks ago, and the vibration came back pretty quickly (like on the drive home), so this time I called Lexus and told them I wanted the problem fixed before I would take my car back (it's worth noting that they've been cool the whole time, just unable to find the problem).

Okay...so that leads me to today's experience. They had their chief tech drive the car with me. Before we left he had me describe the vibration. He told me that he knew exactly the problem and would know exactly the solution. Basically the GS has pretty loose steering, and I'm not just talking about the substantial boost from the stock ECU (I have the L-Tuned steering ECU). The actual rack has slop built into it. This is fine with a soft suspension, but when I had the suspension stiffened with the L-Tuned shocks/springs and the TRD sways/chassis brace, the slop started allowing small movement of my tires. This was causing both the extremely uneven wear on the rubber and the vibration. He proceeded to tell me that the GS' tires reach harmonics at 42, 62, and 82 MPH which is why I was feeling the vibration around 65. Anyway, he tightened up the rack which has given my GS VERY heavy and solid steering--more so than with the L-Tuned ECU--and he adjusted the toe on the rear and the camber on the front (I'm talking out of my comfort level about this, by the way...just repeating what I heard, which may not be what he said).

Anyway, I'm pretty sure the vibration is gone for good, with the added benefit of two new tires and really solid, heavy steering feel! I've seen several other posts about vibrations at highway cruising speeds on here. You might ask your tech about the steering rack before you give up on a solution.

Hope this helps someone!
Scott

bitkahuna

iTrader: (20)

Very interesting. Thanks for sharing.

rominl

iTrader: (4)

wow, very interesting

i don't have the ltuned ecu yet, but i have tein HA and also a set of 19 with low profile tires. my car is 1998 and i do notice that the steering wheel seems to vibrate a bit at freeway speed. when i pass 80mph it's pretty much gone. i thought if i get the ltuned ecu it might solve the problem but guess not.... i am thinking if it's the same problem as you described. my car is out of warranty already, so i might just go to some repuatable shop and have them "seriously" tightened up my steering rack

///MDex

I'm going to sticky this since this effects so many of us here, and I don't recall a similar resolution ever being discussed. Any additional details you can provide would be great.

Good job Scott.

Murph

Dex,

Actually I had posted about the steering pretensioner adjustment a few months ago during a similiar vibration discussion. The pretensioner does stiffen up the steering quite abit. The drawback is the return to center after a turn is not as quick. It gives the car a heavy steering feel. It's a 45 minute job if you're out of warranty . The pretensioner has a fair amount of adjustment to it.

It reduced my vibration dramatically but I did not get complete relief until I put on L-tuned suspension and did a 4 wheel alignment. Now she's smooth as glass.

Murph

///MDex

Thanks for the heads up. The last couple months, I've been in and out on CL.

FILIPE

I had the exact same problem. I bet u have rims. do you!! This happens anytime you did get the alignment and balance done, or not done properly. You can tell by just exactly what you said. I got my rims put on and had them balanced and aligned. However the steerin wheel shook and so did the seats in the front. noticeably the passenger side when there was no one there. Went to a place here in ct that does alignments only, and problem fixed. Guarunteed this is the problem.

SCWells72

Actually I'm on the stock 17" rims, so no, that didn't contribute to my problem.

Ag02M5

Can you please ask your tech exactly what he tightenend?

I am guessing it is the mounting bolts of the rack itself but can you find out so I can tell my dealer exactly what to do?

Thanks alot and hope it stays vibration-free.

Ryan

SCWells72

Sure. I think I'll call him Monday to ask about when he might be able to try to tune the drone out of my L-Tuned exhaust. I'll get the exact details from him then.

Murph

Just go to a Lexus service dept. Tell them you want the steering pretension tightened. Their suspension tech will know exactly what you are asking for. Beware that the adjustment does change the steering feel. It does feel heavier. I personally like it. I had it adjusted a little at first and then even more.

Good luck

Murph

rominl

iTrader: (4)

yeah, more details on exact the part to tighten up would be great. i have to say not all dealers are that professional to understand what you talking about

rominl

iTrader: (4)

so are there any way to tell them "how much" to tighten it?

Ag02M5

I didn't see your original post...thanks for the info.

I think the steering feels much too light so I will get this adjusted for sure!

Thanks.

Ryan

oldguy

SCWells72
Please let us know in 4000 miles or so if it is still gone. Several have thought this problem fixed, but no one has said that after some miles, it is still gone. Not that they have said it's back, just they haven't said.