We’ve owned a 2010 GL450 for about four years and luckily haven’t had any Airmatic Issues. As of today it has about 77k miles and rides about as is did when we purchased it—rough.

The airbags clearly don’t have any leaks and I’ve had the lower control arm bushings replaced (2x), end links replaced (2x), switched the run flats to non-run flats. The ride height sensors have also been replaced.

I’ve fiddled with various tire pressures, etc.

No matter what I do, I can’t seem to get the legendary floating on air sensation.

We live near a cobblestone street and when I drive over it, I feel every small frequency in the road (can also hear a rattling or clunk from passenger side front). The big bumps (the ones that rock the car) are absorbed.

A Toyota Highlander (Uber) is way smoother. Is this how it is, or is something else the matter?

Could it be possible that—and excuse my limited knowledge of struts—that the airbag portion of the strut is fine, but the shock absorber portion is worn?

My independent mechanic doesn’t seem to notice the roughness of ride, but they also delivered my car with a crooked steering wheel (post alignment) which I had them correct with a second alignment.

On that last note, any recommendations on independent mechanics in the NYC areas that can handle a GL450?

Is my car too old to get a dreamy ride?

 

It could be a bad valve block.

 

I like that idea as it would be an easy fix. Does the valve block function independent of simple raising and lowering? The car easily goes up to Raise mode and then down when the Raise car button is pressed…

 

What size are your wheels and tires? How is the wear on the tires? Have you replaced them while you've had the truck? I wouldn't discount the shocks, either. Does your truck raise and lower as expected?

I have a same vintage 550 with 21 inch wheels, I feel the smaller imperfections on the road, but large speed bumps are almost unnoticed (the latter compliments of the shocks mostly). My tires are 295/40 - pretty wide footprint and moderately low sidewall. Higher sidewall will absorb the imperfections better. If the tires are run flat, they'll be less forgiving, I think, and transmit the annoyances even more from the road surface.

I also run a winter setup on 255/55R19. Winter tires are softer generally and the ride is noticeably smoother, although not as quiet but that's a well known side effect of winter tires.

 

Yes, the car raises and lowers just fine.

I replaced the original Bridgestone run flats two years ago with 275/55/20 All Weather WR G4 SUV Tire from Nokian. The tires improved the ride, but not considerably. The same general suspension sounds. On the highway, the tires are a bit louder, but smoother.

In the four years I’ve owned the car, I’ve only placed about 15k miles on the vehicle so it’s mostly parked and driven around the city (oil changes at 3k).

 

I saw you replied about raising/lowering just before I posted lol if you have no issues raising/lowering, I doubt the valve block is an issue.

Check your shocks for leaks. I'd also raise the truck and leave it parked over 3-4 days to see if it may drop. Here I'm assuming you usually have it lowered when you have it parked? Measure the height at all corners with a tape measure and compare 3-4 days later.

You mentioned suspension sounds. Not sure how related bushings are to the ride quality you describe, but have a look at all bushings front and rear and the sway bar end links. Also check the ball joints while you're under the truck.

P.S. very nice choice on the tires!

 

Thank you! Yes, the tires are great in snow for sure! I will raise the car and check levels after a few days…easy to do as it sits in parking garage for weeks on end. Appreciate all the thoughts on bushings etc