amgnut

iTrader: (1)

Hello everyone! I have had a 2017 GLS 63 for about 15 months now. Currently at about 12,500 miles and have been noticing for some time now that my car is very unstable at all speeds. It feels like it’s really windy out and the car shifts side to side non stop! A few months ago I was at my local dealer and there was another gls63 there and I had parked next to it. The sales manager asked me if I ever felt any wandering on roads in my car which at the time I hadn’t noticed. I asked why and he said the other one that was there was being bought back by Mercedes because of the very issue that I have begun to notice. That vehicle only had about 4000 miles on it though and they had the problem since the day they bought it. Mine hasn’t always been like this so I’m wondering if it’s an alignment issue or if there’s something more to it. Oddly enough my rear tires are at the wear bars, fronts less than half worn and I ran snow tires last winter for about 3000 miles. Has anyone else experienced anything like this? I’m going to take it to the dealer tomorrow but I already know they are going to blame my aftermarket wheels(factory original Continental’s are mounted on aftermarket 21 inch wheels). I also have a gts that I put on vorsteiner wheels and had an issue with a pad sensor at 1300 miles and they denied the warranty claim stating that the aftermarket wheels caused the sensor to short. Again that vehicle has the factory original tires on it too, just nicer wheels.

Pics for attention

Mitch Alsup

What kind of air pressures are you running?
Are you setting the steering to "sport" mode?

I am at 12K miles (also) but I still have over 1/2 tread life left.
My GLS is noticeably sloppy in comfort steering mode (C and I with Steering=Comfort); S (or I with Steering=Sport) gets rid of the sloppy steering feel.

fatmatt0116

Keep us posted on this.

Scorpio550

ive been having this issue took car to dealer more than once, i have been having issues with MB cars more than any other car i have owned

c4004matic

You are absolutely right they are gong to blame your aftermarket wheels and..... they are right. If you use aftermarket wheels that dont meet the same specs as oem you will affect the vehicles performance. Modern cars like your AMG are very different from old fashion cars. There are a multitude of electronic systems that are calibrated specifically to those OEM specs, particularly, AMG vehicles which are even more tailored (negative camber, wider track etc.). Screwing around with the recipe is done at your own risk.

amgnut

iTrader: (1)

The wheels I put on the car were exact spec as oem. In fact I used the original continental tires that came on the car from factory. Camber, track, offset, etc all same as factory spec.

amgnut

iTrader: (1)

I played around with the air pressure and the results were the same. I was running 36 up front and 38 in the rear, then increased all 4 by about 2 lbs then by 4 lbs...didn’t do much for the instability. As far as comfort/sport/sport+, all behave the same with regards to the issue I’m feeling.

amgnut

iTrader: (1)

I think I was mistaken about mb buying the other gls back. I spoke with the service manager today and he indicated initially the dealer was hoping for a buyback but mb sent engineers and determined the vehicle was performing as designed and there was nothing wrong with it. I believe the dealer got him into something else and wholesaled the vehicle.
So today i swapped over to factory wheels that have Pirelli scorpion winter tires mounted on them. I have these inflated to 42 in the front, 46 in the rear. I drove about 100 miles on them and it is def driving a lot better! It’s still slightly skittish, but it’s much more controllable. I’m leaning towards the stock continental tire as part of the problem. The service manager also stated that they believed the tires were part of the problem as well. He also stated something about a “live sway bar” which I have no clue about but I will explore that further when I go back to the dealer later this week for another issue, my GLS really likes to drink coolant so I’ll keep everyone updated as I get more answers.

c4004matic

The live sway bar is the active curve system. If they are faulty you could definitely have wayward handling that would pop up unexpectedly. For example firming up when they should loose for example in straight ahead conditions. On my c400, when airmatic had a fault (twice) they defaulted to the hardest setting. I have read elsewhere about issues with the curve system. Personally I hope I get a reliable one. My C400 had multiple issues, though none serious. My E43 has been perfect. From my research the GLS has been less than stellar reliability-wise. Fingers crossed.

fatmatt0116

I drove an '18 63 that was on the lot tonight...it had the 22s wrapped in P Zeros and the ride was fine. My guess is this is a tire problem. I've read the continental is a nice soft, compliant ride but perhaps this is a function of a soft side wall.

fabbrisd1

Yes - "42 in the front, 46 in the rear" will be "harsh" - a understatement - try 38/40...

Mitch Alsup

I run 39:39 in my GLS.

When it gets down towards 37:37 the car begins to feel sloppy--not unstable, just sloppy.

fabbrisd1

Good call at 39 -

c4004matic

I personally never run at less than the recommended pressure, particularly on a vehicle with low profile tires like the 63, not only is handling worse, ride quality is very much degraded too!
Low profile tires need all the air they can get to avoid flex as much as possible. Lower pressures risks impacts being transmitted from the tire directly to the rim rather than having air cushioning the blow. On 50 profile or more tires the pressures are not so critical, but very low profile tires should be kept within a couple of PSI of maximum recommended pressure at all times Not only will the car handle as its supposed to, it will, paradoxically, improve ride comfort.

amgnut

iTrader: (1)

42/46 on Pirelli scorpion winters is just fine, not harsh at all. The problem was with the continents at any psi.

carlosamg50

Reviving this thread, i have a late 2016 GLS63 and it has factory 22” wheels on it with P Zero M01 tyres all with atleast 6mm of tread.

My car wanders in the road, has a horrible vibration from around 55mph to 85mph which is at its worst in S mode, better in S+ but still there.

It was sloppy at factory pressures so Ive put it to 39/41 and its better but I still feel like the control arm bushes are shot even though MB say they are not, can turn at slow speeds and get steering shimmy but only sometimes. The vibration at speed is all the time, wheels and tyres have been road force balanced, didnt solve it. The vibration isn’t dictated by engine speed, road speed effects it.

Body roll is not what I was expecting, C is arguably better than S, S just doesnt know what the f**k its meant to be doing, doesnt plant the vehicle at all.

Overall the AMG doesnt give me any inspiring feel at speed, at 70mph its shaking and rides like a galloping horse that thats drank a gallon of beer, almost like the wheels are coming off.

Sport + is the best setting, it seems like it knows wjat its meant to do unlike S, but is harsh for constant use, C is too soft but more controlled than S if you know what I mean.

It was like that on Conti’s when i got it so swapped to P Zero and no difference.

Disappointed in the vehicle after only a short ownership.

Thanks

matarile

I must say I am not loving the 2018 GLS63 I just got. Brakes rotors and pads had to be replaced after 1 week (mind you, this is a CPO and that’s why they did the brakes free of charge, because the car was only 1 week in my possession, very unlikely that I had so much fun as to warp both rotors beyond repair). But now there is a strange steering feel that’s similar to what’s described in this thread, so taking it to the dealership in 2 days. I will ask them to check whether the active curve system is failing