QuestionQUESTION: Hi Robert. I have a Mercedes E280 1999 model A/T and I have a vibration on the car that feels like wheel balancing but is not. I have replaced shocks, had balancing done, sent it to Mercedes, but no solution yet. Please help!!
ANSWER: David,
A little more information is needed.
This vibration, is it high frequency or a low frequency? If you were able to place a glass of water on the dash would the wave inside the glass be large of small?
Is it all the time?
If not all the time what speed does it come an go?
Is it more prominent when decelerating or when applying the breaks?
Is this a Gas or Diesel vehicle?
Robert
---------- FOLLOW-UP ----------
QUESTION: This vibration, is it high frequency or a low frequency? If you were able to place a glass of water on the dash would the wave inside the glass be large of small?
Hi Robert- Answers to your questions:
It only vibrates between 90-110km/hour-it is definitely speed dependant.
It is more prominent when braking.
It is a gas vehicle
AnswerThese are probably going to be trial and error fixes.
It seams to me that this may be a case of tread separation ib one of your tires.
Or there may be a slite flat place on the tread. A flat spot will increase over time because of the slapping motion on each revolution.
You may want to take the car to a shop that can spin the tires on the auto to balance.
If the vehicle is untrue in track and wearing tires, you may be going through a tread wear transition causing a harmonic imbalance.
What mileage is on these tires. How old are these tires. What mileage is on the vehicle.
If you switch the tires from front to back. Keep them on the same side. You will probably note a change in the vibration. If it is one of the rear tires, you will see an increase in the problem each time you apply the brake.
Because the tires become gyroscopes at speed, any attempt to place the breaks on the spin will cause a defined wobble during the rate decrease.
This wobble is amplified in the front suspension.
Conversely,if you move the defective tire to the rear, there will be a change in the vibration. Probably less feel.
If your tire shop has a tire truing machine they may be able to detect a tire that is out of round or has a high spot. The machine is used to shave off the high spot. Only recommended if the tires have lots of tread left.
If the tires are OK, I would begin to look at suspension wear.
The issue of tread separation if one of real importance. The separation causes a high spot and as the separation increases there becomes a real danger of sudden failure and the resultant damage.
Good luck and let me know how things go.
Robert
