6.3

That wobbling sounds like my mothers Datsun 240C she bought new,it had some sort of radial tires that had high side walls,the car used to flex on the tires,pumping them up fixed it to certain degree by wore the center of the treads out..[:I]

...There are old cars,and then there are Classics..(Mercedes Benz Ad. 1999)

Thanks again, all.

I'm pretty sure that 4495 is indeed tires. I've now driven each car, one after the other, and there are subtle differences. 4495 is by all standards the worst. Really bad. Now I have to decide whether to put 15" wheels on it first. May move the 15" wheels from 4785 to 4495 just to keep 4785 original since it is a 38k mile car. The 3.5 coupe is not nearly as bad, and neither is 4785, so those likely could be balance, even though they have been balanced off the car.

It really can't be the flex coupling, since that was just replaced in Costa Mesa with a part from the classic center, by Maurice Lavois.

Also, the vibration is definitely at tire rotation speed, not driveshaft speed. And, in 4495, the steering wheel vibrates up and down rather violently.

At low speed, and I mean crawling speed, it felt to me today like the tires were "wobbling", a sort of side to side motion. Hard to describe, but I swear you could see the star sort of wobble side to side at very slow, walking, speed. I feel reasonably sure something has happened to one or more tire on that car internally.

The other cars may just need a "more precise" balance job, on the car.

Mike

Theres some good info here too.
http://www.yokohamatire.com/pdf/tsb-TireBalance-12803.pdf

...There are old cars,and then there are Classics..(Mercedes Benz Ad. 1999)

Mike,
I'll also punt for tyres. Many tyres are unbalancable. We had some tyre guys who spoke at one of the local club meetings. We are given the impression that the tyres are just out in one plane and that putting a balance weight at one point on the rim will correct the problem by counterbalancing the opposite side, the same as the counterweights on a steam engine driving wheel which balance out the thrust and weight of the driving rod on the opposite side. But many tyres are out of balance at several points around their circumference. The rotation dynamics (centrifugal forces)of the out of balance segment will depend on the speed of rotation so it is in balance at a certain speed and out of balance at another speed. The same thing applies to the wheel itself. M-B wheels generally are of the highest quality and the problem is mostly confined to the tyres. You need to talk to someone with a good knowledge of tyres and a really good computerized tyre balancing machine. You may then find that you need one two three or four new good quality tyres.
Art

Mike - hope all is well!

I'll take a stab at this and suggest you check the front flex disk; I seem to recall a similar vibration before finding out my flex disk was loose on the way to Charleston Lodefest.

Someone else can certainly correct me if this is my bad memory or simply off base.

Francis E. Abate

The simple way to check for a wheel&tire problem would be to swap with the car that doesn't have a problem.

Chris Johnson
If you aren't constantly IMPRESSED with your car, then it needs fixing.
100.012-12-000790
109.018-12-000019
109.018-12-003834
www.300SE.org

Is it possible that the hubs could be off balance? Anyone ever see this??? I have not.

No Dan, never seen that, but it is always possible, that a balanceweight is lost/missing. Also possible, that if one mountingbracket of the hubcap is missing or one not equaly mounted on 90 degrees there is a unbalance.

Mike, all three!!! This is real odd to say the least. Next idea because I'm still 99 % sure it's tire related. Try balancing them "on the car". Years ago there was one place in all of Portland that did this. I had a wheel problem with two sets of Zenith Wire wheels (misquided youth deal). The balance job on the car worked. It's thought by safty guys in the government, as being a tad dangerous. I am not even sure we can even have a car balanced mounted on the car, at this time.
Is it possible that the hubs could be off balance? Anyone ever see this??? I have not.

Thanks to everyone for the thoughts, but I don't think we've hit it yet, unless, of course, things are different on each car.

The tires on 4785 are new, less than 3,000 miles on them. We've balanced them SEVERAL times, to no avail. I do think that on the car balancing could be a try at least. It has 15" allow wheels as well.

On 4495, the tires were balanced in California, by Maurice at Maurices Mercedes in Costa Mesa, and put immediately on the road for the 2,500 or so miles I drove to San Francisco and then home to Kansas. By the time I got home, it seemed things were much worse, almost undriveable above 70mph. Admittedly the tires on that car, which I just bought, are not the best. I actually bought the car in Pennsylvania then drove it 6,600 miles, to Florida, California and home. This car has original 14" steel wheels.

The W111 car has what might loosely be described as "Buick" Michelins on it. They are white wall, and I don't recall the designation, but they are not really "proper" tires. They are in good condition though, and I'd think would be satisfactory.

The vibration is definitely at tire rotation speed, not driveline speed. 4495 was checked at Maurices and indeed a new flex coupler installed, but no change. The front subframe mounts were also replaced as well as 3 air bellows. No change. Car drives fine, in terms of steering, etc. No pulling.

It seems odd that all 3 cars have essentially the same problem. The only one that does not is 5064. It has 15" steel wheels and Michelin MXV tires, which honestly I've had trouble with on some other cars in terms of uneven tread wear.

Mike

Mike,

I have experienced the "cycling" vibration in the steering wheel you mentioned, usually at speeds above 75 mph, and have gotten rid of it by having the wheels with tires mounted balanced off the car. The problem seems to occur most often after long periods of the car sitting during the winter, and may be related to the flat-spotting mentioned above, but I have never been able to pin down the cause(s) definitively.

John

I have the same problem at 80 mph.
This vibration is caused by the tyres.
I have the V-rated Fulda tyres and it seems that more cars with these tyres shake at a certain speed.
Funny thing is that when the car vibrates you accelerate or slow down and the problem is gone for a while.

Werner

99 % chance your problem is tire related. I have had this before on a 560 SEL in almost new condition. In our case, you could feel the vibration between 80 to 100 MPH. After 100 it was fine. Installed new tires and it was fine.
Ever hear of haveing a set of tires "Trued"? We did this in the 1960s but not since then. I hink it is easier to ditch your current tires and buy a new set.
I don't think this is a flat spot, BUT OLD tire. This is maybe a 10 % chance. I have witnessed this ailment. Our Flat spot tires worked out of it after about a 5 mile drive. Meaning: once they warmed up, the dry rubber became more flexible and the vibration / bounce was gone.
You might feel something similar if you hit the brakes and locked up the wheels for 100 feet. Discovered this problem on a large truck but never on an auto. If this is the case, the bounce would be there, at every speed. Less at high speed but still there.

Heres another thing to think about,when you do the front axle mount bushes ,the cross stay,that little rod with adjustable ends has to be loosened off .
The gearbox mount has to loosened ,and possibly the drive shaft center bearing.
With the car on a hoist,ensure the car is at it's correct height and the weight is on the wheels.Loosen the 8 axle mount bush bolts .
Then retighten everything with the weight on the wheels.This ensures the front end is in a natural position in relation to the weight of the car.
Make absolutely sure the sliding joint on the front half of the driveshaft is in good conditon with no radial play.If it is dry it will also cause strange noises so ensure it's greased regularly. Look particularly closely at the center bearing mount.In the case of indeterminable noises etc i remove the drive shaft and check the conditon of the center bearing,it's mount and the rear universal joint.
The Front wheel bearings must be in good condition ,The Proceedure to check them is to use a dial test indicator ( DTI) and turn the wheel to measure the play.
There is a specific amunt of play.If there is too much ,the wheel bearings run hot and noisy.
Too little and the bearings will also overheat and fail .
If the bearing play on the front is within specs,Check the rear wheel bearings.
Once you are absolutely sure the bearings are all perfect ( we aim for nothing less) the wheel alignment needs to be adjusted using a front to rear laser alignment rig.
Of course,while you are using the DTI measure the rim runnout to ensure the wheels are infact circular in all respects.
Finally I would get the wheels balanced ON CAR.
This is the only way to ensure the wheels are balanced along with the disc rotors etc .
Are you using inner tubes ?.Radial tyres should never have inner tubes as these both unbalance a tyre and the flexing of the tyre case wears lines in the tube which eventually cuase a flat.
At the speeds you mention,what is the engine speed in Revs per minute?.
Have you tried driving in a lower gear to replicate the vibration ?
.You must try to elimnate other sources of vibration such as loose exhausts,fan clutch worn out slipping transetc etc .



...There are old cars,and then there are Classics..(Mercedes Benz Ad. 1999)

At 60 mph and over, I had a constant "drum", which seems to have been resolved by replacing the bushes in the rear suspension. I still have the rear sway bar bushes to do, so it wasn't caused by those ones.

I just eliminated a vibration problem on one of my cars by replacing the rear brake drums with new ones, maybe you have a rotor or something else out of balance? Or a driveshaft problem with something out of alignment or out of balance. It has to be something that spins when the car is moving, if that is the only time it vibrates.

My father got some new tires on a Cadillac of his a few years ago, and they vibrated from day one. He put the car on a jack at his house and spun the wheels and one of the tires was out of round from the factory, and it was a goodyear tire, not a brand x one.

If your cars are limited use and sit for long periods maybe the tires hardened up or flat-spotted.

It is funny the way a vibration in a car on the highway will cycle, as you say your being 3 seconds. I guess if you have two components out of balance rotating at different speeds, at some times they will cancel each others vibrations out, and at different times they will combine and amplify each other.
If one tire is a little bit different diameter than the rest, which is very common in production tires, or if the air pressure in one tire is high or lower than the rest, and one is out of balance a hair, or the rotor on that wheel, it might be cycling it's vibration with something else on the car that is out of balance, another brake component or the driveshaft. The sky is the limit....

That is all I got!

Good luck,

Benjamin


300sel6.3 #495

I'm curious if anyone else has what would seem to be tire balance problems, but is not cured by balancing the tires! In 2 109018 cars and one 111026 car, above about 70 mph I get a sort of periodic vibration in time with wheel rotation. It gets worse, then better over about a 3 second period in all the cars. Tires have been balanced by different shops, and the problem still persists. Shocks "seem" to be fine in that the cars do not "bounce". One has new supframe mounts, one new shocks, etc.

One had Michelin MXV tires, one Goodyear, the other is Michelin but not really highspeed tires (11026).

Anybody else have this?

One car I have, 6.3 5064, does NOT do this.

I just drove 4495 6,600 miles, with a tire balance in the middle of the trip and it still vibrates horribly at 80-90mph.

Conversation will be appreciated.

Mike Coup