Hello,

We just took our annual trip down to the beach in my 2022 GX with 40k miles. Most of the 6 hour drive was on the highway going 70-75 mph. While cruising at these speeds, I’m experiencing an unusual vibration that can be felt in the seat and steering wheel. The best way I can describe it is like driving over rough pavement for 1-2 seconds and then back to smooth pavement 1-2 seconds later. This will happen for several miles and seems to go away when I slow down to 60-65. I’m very familiar with the typical unbalanced tire vibration but I’ve never experienced this before.

Here is some additional background. I have Nitto Terra Grappler G3s (stock size) with 5k miles on them. A few weeks ago I rotated them for the first time and immediately felt vibration in the steering wheel. I took it back to the tire shop and they did another road force balance of all 4 tires. They said all 4 needed some slight balancing. I didn’t notice this weird vibration until after this second balancing attempt. Could it be the tires? Something completely unrelated? If it is the tires then I may be getting rid of these much sooner than I had hoped.

 

... lug nuts properly torqued ?

 

I sure hope so! It was one of the best tire shops in the area and the only one I trust not to damage my wheels. My plan is to rotate the tires again when I get back from this trip to see if that changes anything to help narrow this down.

 

... no issue for 5,000 miles ... rotate/balance tires, then an issue ... front tire imbalance obviously translates into the steering wheel ... rear wheel imbalance will cause the passenger seat headrest (as a visual indicator) to vibrate. So could be the front-to-back rotation, a thrown wheel weight ... less than torqued lug nuts ... or a transient road condition.

The fact that the vibration is intermittent obviously clouds the situation ... hence your posted question ...

 

Yeah you bring up a valid point about the lug nuts. I will probably check those before we hit the road to head back home. The tire shop did another rotation when they rebalanced the tires which essentially undid the rotation I had done. I can’t be angry about it since they probably thought it was due for a rotation. I’ll be curious to see what changes, if anything, when I do another rotation this weekend.

 

... a wild point ... alignment ... insufficient Caster can cause a "Death Wobble" that is set off by road conditions ... so is a random event ... and can last for seconds or continue until speed is reduced (without using brakes). Have never seen a Lexus post siting Caster / Death Wobble ... so does not appear to be inherent to the GX platform. This would not explain why your problem did not exist before initial rotation/balance.

 

Assuming that the nuts were properly torqued...this is a long shot. Were the tires mounted with the valve stem aligned with the dot on the sidewall of the tire? That dot is supposed to be aligned with the valve stem on the wheel to achieve best balancing (something not a lot of tire installers know). Given that the tire you chose has an aggressive tread, and possibly stiffer sidewalls, the dot might come into play.

 

Bad tire? I'd do my own experiment, rotating a few times while checking for changes in the "vibration."

 

It could very well be a bad tire. One other thing worth mentioning is I did a 5-wheel rotation so this is the first time using the tire installed on the spare. I marked the wheels under the center caps so I can keep track of which wheel is where. I’ll be rotating them on Sunday when we are back home. I’ll likely do a 4-wheel rotation this round and see how it feels.

I seem to have the worst luck with out of round tires. On my 4Runner, I had to replace two new Cooper tires after 3 attempts to balance them failed. Then I replaced those with Michelin Defenders and had the same issue. One of them could not be balanced by Discount Tire. On the third try they damaged two wheels and had to have all 4 refinished. They ended up exchanging those for some Bridgestones which were perfectly balanced for most of their life. If these can’t be balanced properly then I won’t keep them long. I don’t have the patience to go through this yet again.

 

Was there a significant tread depth delta with any of those tires, especially the spare? If so, maybe a speed "differential" triggered harmonic (center diff).

 

Now that’s an interesting theory as well. With just 5k miles I wouldn’t expect much of a difference in tread depth but maybe these GXs are more sensitive to it given their full time 4wd drivetrain? That’s something else I’ll consider. Maybe I will move that tire back to the spare location. Lots of variables here.

 

Nitto tires are one of the best balancing truck tire in my experience and per the majority of reviews and forum posts ... but imbalance and out-of-round does happen. Discount Tire is very good at flagging a new tire that is outside of normal balancing parameters.

... eliminating the spare as a variable is good idea.

 

I think you are probably good. I missed the small 5k miles difference.

 

Simple answer IMO - One of the rears was slightly off (possibly un-true) and un-noticeable on the fresh install. Only became noticeable when it was moved to front. The road-force procedure improved it, but didn't make it 100% true. I observe this ever-so-slightly on rotations sometimes where the "Best 2" tires usually (intentionally) end up on the front axle upon installation until they get their first rotation.

Agree that Nitto's are generally A+ wrt being true and needing very little weight. But it can happen. I'd let your tire shop know you are still getting some undesirable vibrations and have them try to road-force again, and rotate bead against the wheel if indicators suggest doing so. Have them confirm runout is in spec too, and kindly request a replacement if close to out of spec.

There's also the certain patches of pavement that cause these vibrations/sounds (I encounter a few of those regularly) - but those will be re-creatable at the specific points of the road. Sounds like you've ruled that out and have legitimate tire vibration issues.

Regarding F/R and tire-size / tire-wear discreps causing this situation via Torsen Center Diff - not likely. I ran a stock 265/70 spare with 265/75 Nitto Grappler G2 tires (basically a "+1") and had a sizable diameter delta on the passenger rear. No vibrations of this sort came about - but Traction Control tripped when going a bit faster around a banked freeway than I should have been going. So I say wear/diameter differences are not possibly the RCA here...

 

Only time I’ve felt a strong vibration was in my LS430, specifically at 70mph. Turned out to be the tires (Michelin X-ice purchased from dlr). Lexus dealer tried rebalancing multiple times with no success. Tires had been manufactured like 1.5 yrs ago. Finally dlr made warranty claim to a Michelin and got new tires manufactured within last 6 months. Problem gone. Now I only buy tires from Costco…high turnover, meaning tires don’t sit for months.