Fried Chicken

So the S500 has a vibration throughout the car. It's not through the steering wheel, but more in the floor and seats.

I've rebalanced all the tires at Discount Tire. I had a rim straightened that was a bit off, although it might have some questionable quality.

The vibration appears around 60 mph, and the "nature" of the vibration changes at around 80 mph.

My mechanic told me it's likely the tires. Currently I have Yokohama's in the front and Conti's in the back. Is there a way for me to diagnose the vibration? I'm considering taking the gopro and mounting it to look at the individual wheels, and potentially even the driveshaft.

Is there a way I can diagnose this vibration? It really destroys the feel/purpose of the car on longer road trips.

doni01

iTrader: (1)

I had the same thing and it was a rear Conti DWS tire causing it. Tire was brand new by the way but was bouncing all over the place. Tire rack replaced the tire, no questions asked. If I was you, I would put the rear tires in the front and see what happens. A better solution is to find some one local where you can swap your wheels/tires just so you can see if the vibration goes away.

ibeforreal

It could also be your transmission mounts. Do you see a slight movement in the shifter when the car seems to be vibrating?

Fried Chicken

I just replaced the rear transmission mount, I don't notice any vibration through the shifter.

I might just go to discount tire and replace the rear tires with Michelins.

Recent research has indicated that above 164kmh the vibration stops and the ride becomes smooth.
Recent research has also indicated the car has a vmax of 210kmh. Is it possible to remove this artificial limit with access to a mercedes computer?

lganski

You should also check the drive shafts and flex disks.

ibeforreal

Iganski is correct, another possibility could be the flex disks. A vibration felt through the center floor of the vehicle can be caused by driveshaft flex discs, which crack and shred, causing excessive driveshaft movement.

Here is a thread that shows what a bad flex disc can look like. http://www.benzworld.org/forums/r-c1...disc-info.html

Fried Chicken

I've already replaced one flex disc, and the front one looks to be in good-ish condition.

I suspect it's the tires/wheels. I'm going to do a special balance and if they're balanced I will go to discount tire and replace the contis with michelins.

thebadmoose

I have a similar issue with vibration through the seat and floor. It starts around 50mph, and gets more pronounced between 60-85mph. I had all four tires replaced with new Michelin primacy mxv4. I still have the same problem. I'm going back to sears to have them re align and rebalance. I'll have my independent MB look at the flex seal.

Fried Chicken

Please let me know!
This seems to be a common issue and really detracts from the point of the whole car.

ibeforreal

@Moose, no disrespect to Sears but I would go to a place that specializes in tires to get a proper alignment and/or balance.

thebadmoose

I know, I was afraid of the same thing. I tried to find these tires elsewhere but no luck. I don't think the vibration is from the tires. When I bought the car it had four different brands of tires all with different tread levels and it had the same vibration. After changing the tires it didn't really help the vibration. I think it might be the flex disc. Hope to find out today.

I do have an appointment with Sears tomorrow to have them look at the alignment (steering alignment is off) and rebalance the ties.

MB-Dude

As I posted in an earlier thread, my S55 had a very bad vibration issue. For me, the issue was very apparent at ~2500 RPM, regardless of transmission gear or road speed. After trying a couple of shots-in-the-dark, turned out to be the torque converter out of balance.

As a test, accelerate moderately from a standing stop, allowing the transmission to cycle normally through the gears. Ensure the engine revs to at least 3000 RPM in each gear. Sense carefully for vibration at a particular RPM point, not MPH point. If you get vibration each time at an RPM point, the problem is before the tranny gears. If the vibration occurs only at a particular MPH point, the problem is after the gears.

Cheers,
Jeff

mrbobby

Mr Chicken, the factory speed limit can be reset by someone with a STAR system. I had it done on my S55 and know for sure that you can bury the speedo.

Fried Chicken

This is interesting, I've never heard of a torque converter being out of balance, however I'm pretty sure my vibration is speed dependent, not engine RPM dependent.

I suspect it might be the driveshaft, or the tires are out of round.

Mike5215

Almost always a wheel problem. Bent (which a road force balance will catch) or excessive run out (which it won't unless they do a separate measurement for it).

I'd rule that out before you spend the money chasing other stuff. These are OEM rims, not aftermarket, correct?

Fried Chicken

OEM Rims, one was bent that I had straightened (front); although the quality of the straightening is questionable. The vibration doesn't manifest itself in the steering wheel. I'd say it's 7-10 Hz.

I will see if I can find a shop in the area which can do the proper balance.
What exactly is excessive run out? How do I check for that?

Mike5215

Sounds like one or both rears may be bent. The tires should be re-balanced on a road force machine and watch to make sure they don't take excessive weights. A couple of ounces at most. Run out is a horizontal variation in the wheel. It causes it to wobble laterally versus up and down. The shop can check for run out while the wheel is on the road force machine. Best bet for wheel problems is the MB shop with properly calibrated road force machines and techs who know how to run them.

thebadmoose

Update on my vibration. After having the wheels re-balanced and re-aligned the vibration has decreased significantly. There is still some there but I think it's the wheels. The place I got it done at didn't have a force balancer. I'm guessing they didn't balance the wheels when I bought the tires and did the balance when I came back.

Mike5215

Yeah, a road force balance may get it perfect. Tell them you want the tire broken from the rim and repositioned before they spin it. Sometimes you get a high spot on the tire that happens to be on a high spot on the rim and just rotating the tire 45 degrees on the rim and remounting helps cancel the high spots out. Then the regular road force balance takes the rest of the vibrations out. It's not likely they actually aligned the car either. Any shop so poorly equipped not to offer road force balancing doesn't have the specialized equipment unique to aligning a W220. I'd get the car to a dealer for a true four wheel alignment and road force balancing. While the W220 is now cheap to buy, they still require the same attention as when they cost $90,000.

tusabes

Everyone always says the mb dealer is the best place for alignment as they do it right
Most independent shops don't align Mercedes right

pjkwong

My indy check my front wheel bearing and he tighten up the adjustment in the front and it got rid of my vibrations, it could be that.

ibeforreal

My Indy guy does just about anything a MB dealer can do and for a lot less money. I generally buy my tires from Tire Rack and have them shipped directly to him. Watching him balance wheels with some of the technology he has is a work of art in itself. I just had him do a 4 wheel alignment and replace my lower control arms and the results are absolutely amazing.

I have never seen a shop, not even MB with so much software and hardware technology. He probably has close to a million dollars worth of equipment.

Fried Chicken

My indy is the same way, however, I would still trust a mercedes dealer's quality over his.

ibeforreal

Not me. I have had my experiences with MB service.

Mike5215

Every good MB indie started out at a franchise dealership, but the dealership guys are under added pressure to produce revenue. The Indie guys often split off because they'd rather just take care of their customers. MB doesn't make it easy though. The cars get more and more complex tech wise and often the Indies get shut out. My Indie shop looks like a museum now...nothing much there after 2006 anymore.

Obviously it no longer applies to the 220 but I always buy CPO and trade before the warranty is up. Just drop it off at the dealership, get your loaner and come back when it's over.