vibration from 65 - 80 miles

[Bruno_300TE]

Hi everybody
When driving between 65 to 80 miles I experience some vibration in the steering wheel (It is gone above 80 mph). Sometimes it is hardly noticeable, other times I can even feel it in the accelerator pedal. The tires have about 4000 miles on them (Yoko Avid 4s). I had them rebalanced on a Hunter 9700 balancer - it helped somewhat (vibration started at 50 miles before). Rotating tires did not improve the condition, nor did relieving possible stress on the exhaust system. Reading through posts on this forum, I replaced the steering damper (had a big dent) and also the intermediate bearing (including mount) of the driveshaft. The flex discs are fairly new too, as well as the whole suspension (control arms, shocks, links, mounts etc).
The tire shop that rebalanced my tires told me that my rims are not round anymore, and I would probably need to recondition them.
Before I go for the rims (expensive), are there any other possibilites worth checking? Could wheel bearings be responsible?
Your sensible comments are most welcome!
Bruno

[1991300SEL]

How's the alignment look?

[Bruno_300TE]

Thanks for your comment. I had the alignment done at the dealership after the suspension rebuild - everything is supposed to be in spec.
Bruno

[lino]

I had a problem with the Yokohama AVS dB S2 and the tire shop switched the tires from wheel to wheel front to back and with a little time and wear it went away. Sorry, I don't have anything to explain this better. That's what happened to me. I bought a set of Yokohama Avid H4S after that set and had no problems with them. Persoanlly, I think it has something to do with the condition of the rims and the person who balances them. The problem happened to me the day of installation.

[G-Benz]

I'm having this problem now (and has gotten worse over several years), and I'm convinced that I have a rim problem.

Fortunately,I am in the market for some 17" rims later this summer, so I hope to get that issue snuffed!

[pmckechnie]

I had a problem like that on my 84 500SEL. I had 3 different sets of tires, 2 sets of wheels, alignments, balance (many times), and the problem would change, maybe go away only to return later. Rebuilt frontend (needed it anyway) and nothing helped until I changed the steering damper. Nothing else was done at that time. That was about a year ago and the car has been smooth as glass since. If it hasn't been replaced I would do that next.
By the way, one set of the tires that were on the 500SEL are now on my 91 300D and they are fine on it at any speed.

[emmydotnet]

I had a similar problem. Intermittent vibration at about 65+ mph. Balanced with Hunter did not solve the problem. Replaced motor mounts reduced vibration to almost nothing. The old motor mounts were separating - i guess they were still the originals. I have a 91 560 SEL with about 165,000 miles .

[Bruno_300TE]

emmydotnet
Interesting! Did you have an idle shake as well? Did you feel the vibration in the steering wheel?
Bruno

[emmydotnet]

no idle shake as it relates to the motor mounts. I say this because I also had a rough idle problem, but was due to electrical issue. Vibration was felt at the steering wheel which was intermittent at speeds between 60-80

[Bruno_300TE]

excellent advice, emmydotnet. I replaced the motor mounts and the vibrations are 60% gone! (For the rest I'll replace the rims.) They lasted 70'000 miles and were compressed by about 1 inch compared to the new ones. I was sceptical that they are responsible for the vibration since the vibration persisted even after I put the car in neutral at 60 mph.
Thanks, Bruno

A bad motor mount on a 124 car can cause some STRRAAaaannge things to happen. They are fluid or something and I've heard some folks say that they have to change them as often as 100,000 miles. The manual transmission cars have different mounts. Maybe that's why I have changed one of them in 280,000 miles.

Good luck,

[sbourg]

Originally Posted by Bruno_300TE

excellent advice, emmydotnet. I replaced the motor mounts and the vibrations are 80% gone! (For the rest I'll replace the rims.) They lasted 70'000 miles and were compressed by about 1 inch compared to the new ones.

Not sure what you mean by 'rims compressed by 1" '? Anyway, our 190E has had a vibration in the same speed range you mention since we got new tires a couple of years ago. Vibration was not intense, nor always noticeable, but it would eventually wear on you. Several new balancings did not help.

Recently redid brakes, replacing rotors and pads in front, pads in back - flushed system. Vibration is now 100% gone. Also adjusted alignment, but that had no effect on vibration, just tracking. A bad rotor can never be corrected by anything you do to wheels, tires, alignment, etc.

Steve

[Bruno_300TE]

Sorry Steve, I mean that the motor mounts were about 1 inch compressed relative to the new ones. Regarding the rims: according to the tire shop that did the Hunter9700 balancing they are out of round. I will therefore replace them with good ones in the future to address the remaining vibrations that are still present.
Interesting point with the rotors - so they were actually out of balance? How was braking? Did you feel some pulsation in the pedal?
My goal is to get the car 100% vibration free - this should not be asked too much for a mercedes, should it?
Regards, Bruno

[emmydotnet]

Bruno_300TE:
glad to hear about your vibration problem 80% resolved....my old motor mounts were completely worn out. The driver's side was completely separated( i mean, the rubber was completely separated from the metal piece...)

[sbourg]

Originally Posted by Bruno_300TE

Interesting point with the rotors - so they were actually out of balance? How was braking? Did you feel some pulsation in the pedal?

Yes, sometimes, but not always. However, the pads were pretty worn too, particularly in the rear. Still, I think it was uneven pad contact over each cycle of revolution causing the problem - when the brakes were not being applied. I suppose the rotors could have been unbalanced, but I honestly don't know how much uneven surface wear would affect that.

Another thing I found was a missing lockscrew on the right front rotor. Potentially, since the rotor then rattles around freely with the wheel removed, a minute amount of debris could have fallen between rotor and hub. This would cause runout when the wheel is bolted back down. I replaced the missing screw.

Steve