Generally harmonics are a balancing issue. The fact that you had a vibration with two different sets of tires could lead to something other than the tires, but that is usually where you start. Have you recently changed or turned the front brake rotors? Had a flat tire?

Having looseness in the front steering/suspension can amplify the vibration, but something spinning has to be creating the vibration before it can be amplified.

Since I like to start with the simple/cheap fixes first, have the front tire balance checked and then you can move to more difficult items. Some performance shops have a tire spinning machine that spin up the front tires (one at a time) to isolate the problem.

 

It's funny that you should mention this. I have a 2002 SLK320 with the same problem at the same approximate speeds. My car vibrates between 70-75 mph. I rarely drive that fast on the Oklahoma interstates so I didn't think much of it, but as soon as I get over 75 mph everything smoothes out again.

 

tires need balancing and/or weights fell off

 

The steering damper is of course under the car just below the oil pan, its a $20 part and takes about five mins to change. It looks like a long skinny shock.

 

Thanks,

Today I made sure I had the torque on all the lug bolts even, I read somewhere that it could be a potential cause - I figure it's worth a shot...I haven't taken it out on the highway yet, so I guess we'll see tomorrow if it changes anything, honestly I doubt it.

I am going to change my steering damper as soon as I can get my hands on a new one - hopefully next weekend. It is likely due to be changed anyway, so even if it isn't the problem it's a cheap easy thing to do and can't hurt anything.

The car did get new brakes just before I bought it - looks like they just turned the rotors rather than replacing them....they look pretty good to me, and I have absolutely no vibrations while braking, but I guess it is still possible that they could be out of balance??

If it is the rotors, or hub, or something like that, will have the wheels balanced while on the car solve this??

 

I am sad...no comment on my input?

tires need balancing and/or weights fell off


wahhhhhh!!!!!!

 

Sorry, I should have mentioned that I ruled that out....Had the OE rims and new tires re-balanced, no change. Installed brand new rims and tires (freshly balanced), no change.

So I figure wheel balancing is not my issue

 

I can confirm the same problem with my 2001 SLK 320.
It does feel like tire balancing issue but I didn't try to diagnose it yet.
I will be watching this thread with interest.

My Honda Civic had vibration problems due to worn out front arm bushings. Obviously the SLK is a totally different car but if you have ruled out tires and brakes I would have a close look at the suspension links.

 

Seems like a pretty common issue actually. I asked my brother about his last night because I was going to try his wheels on my car and apparently his car (98 SLK230) does the same thing.

I have new steering dampers for both cars so I will install this weekend and update the thread with the results.

 

Take pictures and do a little DIY write up if you have time. Thanks

 

Will try to do that!

 

I had the same issue, but for me, it turned out to be 2 slightly bent wheels. I felt it most when the wheels were on the front (obviously) and hardly at all with them on the back. These are after-market, so there's no staggering issue.

 

How did you make out with this problem? Any updates?

 

I installed the damper last week - sorry I didn't get a chance to take any pics. It is a very simply job though, took about 15 minutes from start to finish.

Vibration is much better, but still noticeable if your paying attention to it, and only within a really small speed range (115 km/r -ish)

Looks like I am gunna live with it for awhile now though, time doesn't allow much more playing around with it, and it's not bad enough anymore to really bother me.

Steering feels MUCH smoother and responsive on both cars - well worth the time and expense to change the dampers.

 

I had a very pronounced vibration at 65 mph or so. It ran pretty smooth up to 60, and then beyond 70 mph. The dealer service couldn't really pinpoint the problem, but felt that a belt had slipped on a tire. (Conti's) Since the set had more than 30,000 miles on it, (plus whatever the previous owner had on them) I crossed my fingers and bought a new set of tires, mounted and balanced. The problem went away. Whether the problem was really due to a belt slippage, or balance issue I can't confirm.

I will caution though, as of now, I'm not an advocate of buying tires from a car dealer. Just recently, that set picked up a small nail creating a slow leak; the dealer would do nothing for me. (The nail was marginally close to the tread edge.) The service manager told me that since the MB dealer was not a tire dealer they did/could not offer road hazard warranty - dispite the rather large $$$ I spent on them. Since I had 20,000+ on that set, and with no one who would patch/plug the one tire, I bit the bullet, went to Goodyear and got a new set WITH the RHW and paid less for the same tires. (So I'm safer, but poorer . . . If I only had a garage I might have tried a patch/plug myself, but I would have still been without any form of RHW.)

 

It is also possible that one of your tire is out of round. Tire store that only sell tires have gauges to measure this. I have this problem long time ago in my BMW.

 

Yeah, both good points....Only reason I am shying away from tires as the issue is because putting brand new rims and tires (winters) made no change.....I figure the chances of both sets of tires having issues are pretty slim :S

 

While the vibration is likely to originate in somewhere within the front axle, vibration can start with anything that is spinning. Brake rotors, drive shafts, etc.. Without the ability to spin up each wheel, individually, it could be a long trial and error process to correct it.