Vibrations at high speed

[Matsui]

I have a lifted 2009 GX470 with 270k miles that was driving smooth forever until April, this year and this problem is not going away. The vibrations are primarily on the floor and then also felt with the seats. The steering does not shake most of the time. I've gotten the tires balanced 3 times at a very reputable tire shop. They have also inspected all suspension and wheel components and everything looks fine. They inspected the driveshaft and greased it especially in the front part which they said was very dry. Other than that I got the all the brake parts replaced front and back. The tire shop just did the front wheels road force balance and since we ran out of time, I'm planning to go back to get the rear ones done as well. I'm not sure if that's going to make too much of a difference because I didn't feel any improvement after the fronts were done.

Does anyone have any experience similar to this? This has been stressing me out for 4 months now and I can't even drive in the left lane because of the vibrations and keeping at speed around 60 or less - this is extremely frustrating.

Any advice welcome.

 

[vipergrhd]

Did you get new tires? Any work done before the vibration started? Do you still have the factory lug centric wheel? If you do, they should be balanced with a pin plate to simulate lug nuts applying pressure to the wheel, look up Haweka plate on YT.

 

[Matsui]

No changes to the wheels, tires or lugs for a while when this started happening. Everything has been very well maintained and I've had the same suspension with Method wheels for 5+ years without any vibration issues until now. The tires were replaced a year ago with same Wildepeak AT 285/70.

 

[Rednexus]

I'm wondering if you may have a damaged driveshaft, or it may have thrown a balance weight. If the driveshaft was not being routinely greased it's possible that it's damaged internally (slip yolk or a U-joint) but the damage is not apparent from the outside. A new driveshaft is only around $300 from Lexus (it's an updated part from the old driveshaft), and to be honest they usually don't last much past 200K miles (my slip yolk was worn out well before that). It's a simple job to R&R one.

If you are brave you can remove the rear driveshaft, lock the center diff, and drive it in FWD mode to see if the vibration goes away. Or, just replace the shaft. I've driven my GX in RWD mode w/o a front driveshaft but have not tried it in FWD mode w/o the rear driveshaft. It was fun spinning tires in RWD mode .

 

[Matsui]

I'm wondering if you may have a damaged driveshaft, or it may have thrown a balance weight. If the driveshaft was not being routinely greased it's possible that it's damaged internally (slip yolk or a U-joint) but the damage is not apparent from the outside. A new driveshaft is only around $300 from Lexus (it's an updated part from the old driveshaft), and to be honest they usually don't last much past 200K miles (my slip yolk was worn out well before that). It's a simple job to R&R one.

If you are brave you can remove the rear driveshaft, lock the center diff, and drive it in FWD to see if the vibration goes away. Or, just replace the shaft. I've driven my GX in RWD mode w/o a front driveshaft but have not tried it in FWD mode w/o the rear driveshaft. It was fun spinning tires in RWD mode .

Good point. And this is what I'm really leaning towards as well because I'm running out of options at this point. The only thing left is road force balance in the rear but after not experiencing any improvements with the fronts (which the tech said needed it) I'm not sure if doing the rears will improve the situation.

 

[Rednexus]

Here is the driveshaft Toyota told me to get for my 2007 GX470. I'd still verify for your specific GX as there appear to be multiple variations of this part out there.

https://parts.belllexusnorthscottsdale.com/p/Lexus__GX-460/Drive-Shaft/120393605/3711060A41.html

They've gone up a bit and are $342 right now. Again it probably needs to be replaced anyway due to wear, especially if your slip yolk was dry. It may have a ton of play from wear at the slip yolk, that could easily cause a speed-based vibration. But, no guarantees it's the driveshaft.

FWIW, I grease my driveshaft at every oil change (5K miles), I think my OE one wore out as the previous owners didn't grease it enough.