Again it seems like a friction issue that shows up with speed. parking brake dragging or a sensor on the brakes coming on when it should not. Since some folks seem to have fixed it with a brake mechanical maybe the tech could check those?
GX550 Overtrail Vibration
- Thread starter connorville
- Start date
Not the case for mine. As noted a few times in here, there are possibly two to three different issues being experienced on this thread.
Update on my case….
Lexus put a set of 20” wheels from a Luxury on my OT. They test drove it and said the vibration went away. They put my 18’s on the Luxy and they felt vibrations in it. So now they are waiting for approval from Toyota/Lexus AU to change the tyres over on my rims to try again. They have offered me an opportunity to test drive my OT with Luxy 20” wheels when I am back for the next attempt to fix it. Personally, I hope it is just the tyres as that is an easy fix. Highly unlikely, but maybe there is a defect in the rims? Maybe it’s a dampening issue? I would like to know the weight difference between the OT 18” combination compared to the Luxy 20” combination. Sometimes it feels like the shocks struggle to dampen small bumps. It’s a similar feeling I got in my 150 Prado when I put some heavy AT’s on it. The shocks struggled with the weight, sometimes feeling like axel tramp.
Lexus put a set of 20” wheels from a Luxury on my OT. They test drove it and said the vibration went away. They put my 18’s on the Luxy and they felt vibrations in it. So now they are waiting for approval from Toyota/Lexus AU to change the tyres over on my rims to try again. They have offered me an opportunity to test drive my OT with Luxy 20” wheels when I am back for the next attempt to fix it. Personally, I hope it is just the tyres as that is an easy fix. Highly unlikely, but maybe there is a defect in the rims? Maybe it’s a dampening issue? I would like to know the weight difference between the OT 18” combination compared to the Luxy 20” combination. Sometimes it feels like the shocks struggle to dampen small bumps. It’s a similar feeling I got in my 150 Prado when I put some heavy AT’s on it. The shocks struggled with the weight, sometimes feeling like axel tramp.
That makes sense to me OT. the high speed woulld exaggerate the problem. Those tires only have 7/32 of tread new. I thought that fact was surely intentional for some reason.
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
Appreciate the update. What is Lexus’ next step? This sounds like a case where they need to buy the vehicle back from you. I know 2 other members had theirs purchased back. Is that option for you?
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
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
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.
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.
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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.
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
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
