W124 Vibration at 80 MPH
 

Hi,
My '92 300E rides smoothly up to just under 80 MPH. Once the car hits 80-85 which is the speed I usually cruise at, it shakes quite badly but will disappear over 85. The tires are Falkens which I have found to be excellent up to now and have about 6000 miles on them. The steering alignment was done about 1000 miles before the tires were replaced. I checked the front tires today and notice wear on the inner edge of both tires. Can anyone tell me what is causing this? Do I have to get the alignment done again? Thanks.
Colin Gibb. :confused:

well, yes
 

i would say an alignment is in order.

tom w

check your air pressures first and formost.
then get your tires BALANCED and rotated. see if the shimmy/ vibration changes from steering wheel to seat or vice versa.


failing that you have bigger problems. steering shock, trans mount, suspension bushings etc. all play a part.

You probably have two problems. Alignment won't cause the shaking you describe. I would rebalance the tires. As to the tire wear, it sounds like you have a towed out condition. I would check with other people around town to see who does the best alignment work. Check with the repair facilities for their advice. All alignment personnel are not the same. Also it is rare, but a steering shock can cause that shake.

Hmm. You may have a mechanical problem, but I would also recommend slowing down!! The US doesn't have the autobahns as far as I know!!

How many miles on this car? Could be ball joints, tie rods, differential mounts, etc etc etc.

I would find a shop with a Hunter Road Force balancer. In my experience this is the best balance around. Google on Hunter Balancers and go to their website. They have a shop locator module. This machine will give you a printout for each wheel. It will also pick up any out of round condition on a wheel.

I would use the dealer for alignment. Your's is obviously screwed up.

As to the counseling about not going 80, my comment is that around Atlanta you had better be going 80 in the 70 zones or you will be run over.

My '92 Sportline with 230K is vibration free to all the way to 100. I generally cruise at 10 over the limit.

Steve

Thanks for all the advice,guys. I will try a diifferent alignment shop, I have always been a little suspect about the Sears I went to in Warner Robins. See if I can find a shop familiar with Mercedes. The car has 207,000 miles and the steering shock was replaced recently along with new Bilstein struts all round.
As for slowing down, you are right Steve. You better be keeping a good rate of knots up especially on I-75 or I-285 in Atlanta which is part of my daily commute to work or you will be driven off the road even in a Mercedes!
I'm sure it's necessary to crawl around Seattle with all the rain they have, but not here in sunny Georgia.
Anyway, I am afflicted with Lead Foot Disease which in my case is incurable!
Later y'all,
Colin :cool:

Usually all the vibration issues I hear of are solved by correcting something within the tires. I had a Lexus LS that I used to commute in, and it had wicked vibrations at 80+.

Then I read that discount tire has this machine that'll balance the rim and balance the tire independently, then mesh the two into a solution. Worked great - solved all my issues for $35.

Thanks POS, I'll try Discount Tire in Atlanta, see if that cures the problem.
Colin :cool:

Actually we do have Autobahns. German engineering has always been superior to everyone else. Eisenhaur was so impressed with the Autobahn during WWII that the whole Interstate highway system designed in the 50s is patterned after the Autobahn. Once again American engineers screwed up and made perfectly straight roads instead of including the sweeping turns of the Autobahn. It seemed more practical until people started getting bored and fell asleep and crashed.

If you have not replaced your motor mounts, I would suggest them replaced. I had similar issue on my 560SEL. I could not tell by visual on the condition of the motor mounts, but once removed, one was totally worn and separated, and the other was wornout as well....

I would look to
1-the balancing of the wheels
2-to the schok absorber on the steering if you car has one.
3-are the wheel nuts correctly tighten?
4-wheels bearings

My vibration at 65 was just solved by new flex disc and center carrier / bearing.

Rich Mayer
82 500 SL

I agree that the tire wear may only be part of the vibration problem. I suspect the motor mounts,flex disc etc. are contributing to the problem too. I will check these components. Thanks everyone, I'll post again once I've figured it all out.
Colin

As I said, the tire wear indicates an alignment problem which WILL NOT cause the vibration you are experiencing. Also you can check your engine mounts by measuring the distance of the metal part from the frame. If it less than 12mm, you have lost some of the ethylene glycol that fills the mount, and the mount should be replaced. With a failed mount you should have a vibration at idle in gear. If your flex disc is separating, you should feel a vibration at almost any road speed under load.