GX550 Overtrail Vibration

[Michael T]

Man I feel your pain. I’d be frustrated as heck if I were in your shoes. I’m just praying that when I get my 2025 OT+ that it won’t have this issue. Spoke with my sales rep just last week and she said she hadn’t heard of the vibration issue. My dealership has delivered about 30 OT’s to date. She has heard about the squeaky brakes though.

Mine doesn’t have the shaking, but it has developed the brake squeal after 6500 miles.

When I took it in for 5000 mile service, i spoke to the service manager about all the problems I have read on the forum. I told him the brake squealing was intermittent, and he shockingly assured me that it would get worse, and he went ahead and ordered the replacement parts.

I asked him if he’d seen any 550’s with the vibration issue, and he shot straight and said he’d had a few come in for that.

He told me that whatever problems I read on the forums, they know about them well in advance. The service manager straight up told me that part of the problem is that they need to wait to hear from Lexus on how they want certain issues fixed to cover the dealerships ass. He acknowledged my hood flutter as well. He told me the adhesive delaminates from what supports it and that they are waiting for the “official” fix from Lexus on that as well. Awesome dude, but am for sure waiting til the official lexus fixes come down the pike so it can be done the right way

 

[German88]

Update

Today I had my colleague drive along me on the passenger side and observe the tire behavior. We were talking over the phone live. Over a few miles at speeds of 40 on both new smooth pavement and older rougher pavement he indicated it was obvious the right rear tire was bouncing constantly while the right front was smooth as glass.

Looking at the part numbers on lexus parts online for the OT, Luxury, and Premium, they are all different part numbers for the AVS shocks. This leads me to believe the valving is all different in the town tube shocks. The drive mode in directs the ECU to change the ride mode in the AVS shocks from comfort, normal sport, etc.

Based on this information it is my belief that one or all of the following may be causing the bouncing.

Programming is set wrong

Faulty valving in the rear shock(s)

Aggressive valving in the OT for heavier over landing loads causing shock stiffness when roads are not demanding longer travel stroke.

Would love to try sourcing oem rear shocks from the luxury or premium trims to experiment ($571 new) or unplugging the rear electrical connection or just waiting for more aftermarket suspension options available (king, icon, etc.).

Anyone have any suggestions??

Lexus letting us down

I’ve been building and revalving (shim stacks) for over 20 years on motorcycle shocks/forks. Done a handful Fox shocks for trucks as well. What your proposing might be true. Have your buddy look at the opposite left side rear in the hopes it’s not bouncing. Swap the two rears and test again. Also, try reaching out Bilstein, Ikon, OME (Old Man Emu). They will have a replacement soon.

 

[Snooperstyle]

Update

Today I had my colleague drive along me on the passenger side and observe the tire behavior. We were talking over the phone live. Over a few miles at speeds of 40 on both new smooth pavement and older rougher pavement he indicated it was obvious the right rear tire was bouncing constantly while the right front was smooth as glass.

Looking at the part numbers on lexus parts online for the OT, Luxury, and Premium, they are all different part numbers for the AVS shocks. This leads me to believe the valving is all different in the town tube shocks. The drive mode in directs the ECU to change the ride mode in the AVS shocks from comfort, normal sport, etc.

Based on this information it is my belief that one or all of the following may be causing the bouncing.

Programming is set wrong

Faulty valving in the rear shock(s)

Aggressive valving in the OT for heavier over landing loads causing shock stiffness when roads are not demanding longer travel stroke.

Would love to try sourcing oem rear shocks from the luxury or premium trims to experiment ($571 new) or unplugging the rear electrical connection or just waiting for more aftermarket suspension options available (king, icon, etc.).

Anyone have any suggestions??

Lexus letting us down

My dealer and Lexus corporate is doubling down and saying it’s just that all the OT’s are stiffer for presumed overlanding payloads. I’m seriously considering putting Dobinsons on mine and am in touch with them about it. Also, you may have seen earlier in this thread that I did remove the AVS fuse and also the eKDSS fuse and didn’t see a difference. You also may have seen that I added about 1,000lbs of weight and still noticed it, albeit much better.

I’m also looking into putting additional gaskets on my seat mounts until I can get the Dobinsons.

Totally unacceptable that Lexus isn’t doing a damn thing.

The argument that all OT’s are like that for payload is total BS. It is possible to make shocks have a smooth ride zone even if they are stiffer in larger bumps.

 

[German88]

My dealer and Lexus corporate is doubling down and saying it’s just that all the OT’s are stiffer for presumed overlanding payloads. I’m seriously considering putting Dobinsons on mine and am in touch with them about it. Also, you may have seen earlier in this thread that I did remove the AVS fuse and also the eKDSS fuse and didn’t see a difference. You also may have seen that I added about 1,000lbs of weight and still noticed it, albeit much better.

I’m also looking into putting additional gaskets on my seat mounts until I can get the Dobinsons.

Totally unacceptable that Lexus isn’t doing a damn thing.

The argument that all OT’s are like that for payload is total BS. It is possible to make shocks have a smooth ride zone even if they are stiffer in larger bumps.

It’s likely Lexus / Hitachi Astemo Tokico engineers developed a specific shock for the OT/+ models. If that’s the case, I would consider that a good thing. Did they go too far on initial stiffness? Is it a manufacturing defect only affecting a few shocks? Most here It seems are happy with their OT/+ rigs just the way they are. Suspension tuning is a black art and you tune for a certain window which inevitably does not work for some.
I swapped out all 4 shocks on my 23 Bronco hoping to cure “brake dive”. Went with Bilstein 5100’s on the lowest (zero preload) setting. Solved my brake dive but the overall ride quality was much stiffer and in the end I would have rather put up with brake dive and preferred the plush ride from stock (Tokico) shocks.

 

[lekkerman]

After 2 years of i’m waiting my GX 550 over trail plus in eminent white arrived. It had multiple issues which have been reported severe vibration at high speeds over 70 mph hood Flutter and the dreaded lean on the right side of the vehicle.. Lexus Sarasota booked in my vehicle and held it for two weeks. They had a head technician from Lexus headquarters to be flown in to diagnose the vibration and the hood flutter issue. They were able to rectify the vibration with replacing two of the tyres after force, balancing all four and noticing that two of the original Toyo tyres installed at the factory were very high. The hood Flutter was solved by installing foam in the bonnet or hood cavities. I’m happy to report that it now barely moves at 80 mph. The lean on the suspension which was very evident to my eyesight was deemed to be within factory specs. I am including the note which has been provided by the dealership.

 

[lekkerman]

After 2 years of i’m waiting my GX 550 over trail plus in eminent white arrived. It had multiple issues which have been reported severe vibration at high speeds over 70 mph hood Flutter and the dreaded lean on the right side of the vehicle.. Lexus Sarasota booked in my vehicle and held it for two weeks. They had a head technician from Lexus headquarters to be flown in to diagnose the vibration and the hood flutter issue. They were able to rectify the vibration with replacing two of the tyres after force, balancing all four and noticing that two of the original Toyo tyres installed at the factory were very high. The hood Flutter was solved by installing foam in the bonnet or hood cavities. I’m happy to report that it now barely moves at 80 mph. The lean on the suspension which was very evident to my eyesight was deemed to be within factory specs. I am including the note which has been provided by the dealership.

 

[lekkerman]

Here are the original notes from Lexus Sarasota:
I have your GX all set and ready for pick up. A quick debriefing of what we did;

Shaking @ 70mph, we initially balanced all 4 tires, it did not solve it. We tested road force on all 4 and found 2 to be higher than what is deemed 'normal', so we replaced those 2 tyres. All road force balances are well within spec now - as low as a sedan. Vibration @ 75mpg is nearly 95% gone.

Hood fluttering; has been reinforced with NVH and foam to reduce it. There is still some movement, but the hood is designed to have some flex/movement. It is vastly improved with added NVH and foam.

Suspension height; found to be within Lexus specs, there is a different measurement procedure than only measuring from the center of the wheel hub to the fender flare. When measured with the correct procedure, it is well within specs and no problems were found.
--Tanner Stempel Lexus of Sarasota

 

[Snooperstyle]

Article just came out saying Lexus is adding a 1" lift to the 2025 Overtrails. Makes me wonder if they are putting the lift on to kill two birds with one stone (ride quality and clearance). I cannot find any other info on this, but here is the article:
https://www.caranddriver.com/lexus/gx

 

[leopard print]

It is an option and they opened that avenue for me to pursue, however I don’t want to part ways because there’s not a replacement vehicle made that checks all these boxes. It’s amazing except for this one small issue. Sure there are little things they could have. done better like add rear a/c vents in the OT+, more cubby’s for storage etc. the HVAC is poor in my opinion, the awkward transmission clunk when shifting from park but these are all adaptable and easily forgotten about after 3 months. This shake and their blind eye approach to run it down is unacceptable and uncharacteristicly evil behavior of Lexus

Can they just swap you into another GX?

 

[German88]

Article just came out saying Lexus is adding a 1" lift to the 2025 Overtrails. Makes me wonder if they are putting the lift on to kill two birds with one stone (ride quality and clearance). I cannot find any other info on this, but here is the article:
https://www.caranddriver.com/lexus/gx

Interesting if it pans out to be the case. Very curious how they’ll go about achieving the lift. I’ll be paying close attention to the microfiche part numbers which will tell the detailed story.

 

[Snooperstyle]

Interesting if it pans out to be the case. Very curious how they’ll go about achieving the lift.

Yes I am very curious about this as well!! Probably similar to what they do on the TRD Pro 4runners I guess?

 

[JPE]

Article just came out saying Lexus is adding a 1" lift to the 2025 Overtrails. Makes me wonder if they are putting the lift on to kill two birds with one stone (ride quality and clearance). I cannot find any other info on this, but here is the article:
https://www.caranddriver.com/lexus/gx

Interesting that article also mentions that all GX trims will get memory seats. That's the biggest reason I told my saleswoman I now wanted an OT+ instead of an OT. Sure, the OT+ also gets an optional ML stereo (which some people don't like), massage seats, a kick sensor for the tailgate, puddle lamps, lit door sill plate, and the ability to change the color of the ambient lighting. But I'm not sure that those are really worth the extra ~$8k to me. Decisions decisions.

Edit I also wonder where the auxiliary switches are going. My guess would be on the left side of the dash right above or below the memory seat buttons.

 

[jclaffee]

Brake TSB did not fix vibration issue, not surprisingly. Had my 2nd road force balance done - no improvement. Actually worse bc they overinflated the tires to 40psi. Dropped them back to 35 and much better. At this point I think I’m just going to have to live with it. Dealer said they may replace all 4 tires, but not 100% yet.

Sorry to hear that. I REALLY hope they get this sorted out.

 

[farmsink]

Based on all the discussions, research and behavior from my OT+, i'm more confident the issue is the AVS rear specs on the OT+ Shocks. I may try and purchase a rear shock from the premium or Lux models ($64.71) if its the same length swap them out and see what it does. I found this Write up that Motortrend did on the Tundra AVS system which supports either a valving issue or programming issue in the ECU as it works with EKDSS.

Those that have done the new King suspension lift have noted better road manners by getting rid if the AVS but its a price commitment.

OEM Part numbers for rear shock

OT+ Shock - Lexus (48530-69885) With adaptive susp, overtrail/+

2024 Lexus GX550 Shock 48530-69885 | OEM Parts Online

2024 Lexus GX550 Shock 48530-69885

lexus.oempartsonline.com

Premium Shock - Lexus (48530-80B97) Without adaptive susp.

2024 Lexus GX550 Shock 48530-80B97 | OEM Parts Online

2024 Lexus GX550 Shock 48530-80B97

lexus.oempartsonline.com

Luxury Shock - Lexus (48530-80B97) Without adaptive susp.

2024 Lexus GX550 Shock 48530-80B97 | OEM Parts Online

2024 Lexus GX550 Shock 48530-80B97

lexus.oempartsonline.com

Adaptive Variable Suspension​

Customers desiring the creamiest, best-controlled on-road ride will want to order a Platinum or 1794 model equipped with the optional Advance package. This includes the load-leveling rear air suspension, adaptive dampers, and a 10.0-inch color head-up display. The damping system is akin to those of the same name used on Lexus products and on the Toyota Avalon sedan. It features dampers developed by Hitachi and Aisin that feature solenoid-controlled valves that vary the damping by moving a piston in and out to change the size of orifices the shock absorber oil flows through. Damping can be revised as fast as every 20 milliseconds in response to myriad sensors, including several monitoring g forces at each corner.

 

[BAW]

In my case the vibration/shaking was bad enough to make the passenger seat shake very bad. I could be riding along nice and smooth, hit a bump and it would begin shaking. I just installed a Westcott leveling kit and it has almost done away with the shake. It is still there but 90% better. It makes me think the now stiffer spring is over riding the bad valve settings/computer in the shocks to some extent. Just a guess.

 

[Moody1104]

Based on all the discussions, research and behavior from my OT+, i'm more confident the issue is the AVS rear specs on the OT+ Shocks. I may try and purchase a rear shock from the premium or Lux models ($64.71) if its the same length swap them out and see what it does. I found this Write up that Motortrend did on the Tundra AVS system which supports either a valving issue or programming issue in the ECU as it works with EKDSS.

Those that have done the new King suspension lift have noted better road manners by getting rid if the AVS but its a price commitment.

OEM Part numbers for rear shock

OT+ Shock - Lexus (48530-69885) With adaptive susp, overtrail/+

2024 Lexus GX550 Shock 48530-69885 | OEM Parts Online

2024 Lexus GX550 Shock 48530-69885

lexus.oempartsonline.com

Premium Shock - Lexus (48530-80B97) Without adaptive susp.

2024 Lexus GX550 Shock 48530-80B97 | OEM Parts Online

2024 Lexus GX550 Shock 48530-80B97

lexus.oempartsonline.com

Luxury Shock - Lexus (48530-80B97) Without adaptive susp.

2024 Lexus GX550 Shock 48530-80B97 | OEM Parts Online

2024 Lexus GX550 Shock 48530-80B97

lexus.oempartsonline.com

Adaptive Variable Suspension​

Customers desiring the creamiest, best-controlled on-road ride will want to order a Platinum or 1794 model equipped with the optional Advance package. This includes the load-leveling rear air suspension, adaptive dampers, and a 10.0-inch color head-up display. The damping system is akin to those of the same name used on Lexus products and on the Toyota Avalon sedan. It features dampers developed by Hitachi and Aisin that feature solenoid-controlled valves that vary the damping by moving a piston in and out to change the size of orifices the shock absorber oil flows through. Damping can be revised as fast as every 20 milliseconds in response to myriad sensors, including several monitoring g forces at each corner.

All good info, please keep us update! If this turns out to be a fix, I would do this at my own expense immediately!

 

[BAW]

I wonder if disconnecting the shocks is going to make the computer throw an error code that causes problems. At least we would know what the problem was and maybe Lexus would fix it.