Beeson

Hello all! I have a 2007 Mercedes S550 and am experiencing a slight shudder on the highway at speeds of around 58-63 mph. It’s pretty slight most of the time. But others it can be worse (not horrible, but definitely disconcerting.) 90% of the time you don’t notice it unless you take your hands off the wheel momentarily and see it going back and forth slightly in a very quick manner. It usually happens at highway speeds, but occasionally it does it during low speed corners, it almost feels as though the car is crab walking. I’ve read that a bad Transmission Mount can cause this (which is a pretty cheap and quick diy job) but I also wonder if my tires need balancing. I bought the car around two months ago and I noticed it after the honeymoon period. I still absolutely adore the car and know it was taken care of (bought it from a family friend) but just wanna nip the problem in the bud. I also probably need to get the transmission serviced (it has 83k miles now) because I’d say maybe once a month I’ll get in the car and it’ll shift funny. Hold onto it’s gears up to 2200 rpm instead of the usual 1500 rpm shifts I usually get driving like a grandma. Anyways, if I could get some advice that’d be nice. I was planning on getting the tranny mount soon. But if it won’t help anything I don’t think I’ll get it. The only Transmission Mount thing it experiences is a shake when it shifts into gear on a Hill from park. I just use the E brake to mitigate that issue. Other than these small issues the car has been great around 3k miles in. Very fast, decent MPG, and an interior that is better than almost everything today except for the new Creme of the crop luxury cars.

konigstiger

Cost effective first step, have "road force" balance performed. No mention if vehicle is 4matic I attached bulletins for both.

P-B-22.10/01c OCT08 – 221.186 (4matic) up to VIN A127497 humming/vibrations in the engine rpm range from 1200 to 1600 (felt in steering wheel and footwell floor) optimized engine mounts will be installed.

LI00.90-P-050323 – 221 except 4MATIC, steering wheel vibrations/shimmy @ highway speeds. Vibration caused by wheel/tire balance/uniformity; torque strut bushing; or steering rack (vehicles with EHPS up to VIN A351230)

Beeson

I guess I’ll have the tires/wheels balanced this weekend and hope it helps. If not I’ll pursue further. Mine isn’t a 4Matic, so that’s good. This forum is so helpful, thanks man.

Surfer Dude

Have them check the wheels for a missing weight. The other possibility besides the alignment is a bent wheel. Had this on a 2010 S550 CPO purchase with about 35K miles. They missed a bent wheel during inspection. Discovered the same issue you’re talking about after taking possession of the car. Went in for the alignment and they still missed the bent wheel. After alignment, again had the slight feedback your talking back. Went back and they finally discovered the bent wheel. They replaced the wheel and all was good. These are big cars. Someone hits a curb good and its bent. Typically the curb rash is filled and painted and no one looks for anything else.

Vaskata

​@Beeson
Hi. I have the exact same problem. It is on '07 W216 CL550, but it is the same car. The steering wheel shimmers/vibrates at around 55-75 mph. And the strange thing is that this vibration is not there all the time. The cause of this are not wheel/tires, cause I have 2 sets winter/summer and the vibration is the same. And it will not dissapear from time to time if it is wheels related.

So far have changed:
- thrust control arm bushings
- front disk and pads
- front wheel bearings are checked and tightened to spec
- ABC suspention fliud with filter (as it is a suspention component and can be related)
- The sphere on top of the the ABC pump
- The front suspention ABC sphere

And none of this has led to nothing. The strangest fact is that the car does not vibrate/steering wheel wobles until it is cold. The first few miles it is fine. But when all components reach operating temperature (most of the time is driven like that) the steering wheel starts shaking and there is vibration around the entire car. Any ideas?

vettebk

I would check the lower control arms as these carry most of the very weight of the S Class. When a ball joint on these control arms is old, it gives a slight shudder and shimmy around +59 mph. It might go away at 70 mph and then come right back when you get just around 60 mph. If you have never changed control arms with 80K+ miles, I would bet a donut you need them. Do it. A well maintained S Class is the finest motorcar in the World.

nath_h

My 2008 was having the exact same symptoms. I thought it was the wheels/tires, but ruled that out. I recently had the front and rear lower control arms replaced. My car is still at the dealer (has been for 3 months, but that's another story). The tech says my shudder is now gone. I'd like to confirm this for myself though.

Vaskata

Hi, again. Thanks for the sugestion. But what you mean by "lower control arms" - the arm connected to the shock absorber? Meaning the rear lower on the front suspension - connected to the front frame, shock absorber and wheel hub? Or the front lower connected only to the frame and to the wheel?

nath_h

They are parts #5 and #10 on this diagram...

https://www.mbdirectparts.com/v-2008...ion-components

BOTUS

might get further following the older, longer thread - its a design fault due to terrible engineering

it comes and goes because the wheels can sit eccentric on their hubs and as you corner the effect comes and goes (with inside wheels taking a different radius) - sometimes when you sit on the highways it ends up along way out of whack and you notice it

at the weekend my father's w211 E class did exactly this - one way on a 15 mile trip I noticed it and was angry - on the way back it wasn't there - Merc have NO IDEA what they are doing

jack the car up loosen the wheels give them a kick and try and re-tighten them when they are sitting concentric to the hub ... if I was talking rubbish we wouldn't have had people asking for a class action recall for 16 years

https://mbworld.org/forums/s-class-w...ml#post8340717

jaguar...………………………………………………………………………………….. mercedes

vettebk

The car's heavy weight and time/mileage wears on the ball joint on the lower control arms. It doesn't always reveal itself with the classic test of grab the wheel and shake it unless there is a load placed on the suspension. But trust me, if you have more than 50K miles; and you haven't ever replaced the lower control arms as depicted in nath_h's post; it is time. In my opinion, the weak spots on the W221 are the lower control arms especially with the 19 inch rims and the engine mounts. Both wear very badly over 75K miles. On the other hand, after you do the required maintenance, you will be driving one of the finest motorcars in the World.

nath_h

During my very brief drive about a month ago while my car was still at the dealer (again, still is), the suspension felt great w/ new control arms and new inner and outer tie rods. Less clunky sounding. I regret not replacing the upper control arms while I was in there, and it was getting an alignment anyway. My car has 57,000 miles, and had torn boots on 3 out of 4 control arms. The tie rods looked okay, but after I removed them, they were floppy, and the new ones were night and day difference, at least while sitting/testing on my bench. It is hard to know where to stop on these cars. I've replaced so many parts, as I aim to make my car as close to new as possible. But I've got to stop one of these days. I'm looking at adding a nice 2004 CL500, but perhaps should have my head examined first.