[vladmury]

I was satisfied with the M3 arms but after few months my car developed a nasty vibration that increases with the speed. I actually think the control arms picks up the road imperfection and amplifies the vibration. I am thinking to go back to original arms, the combination bilstein b8+ m3 arms is too hard for normal driving and the NVH has increased.

[dwonder]

just started experiencing something similar to this... on 6th gear at around 75, the car gets really wobbly (front and back motion). steering wheel has no vibration. on the same speed on 5th gear, no shaking. what do you guys think - related issue?

[BravoJohny33]

My car has been doing this for years. Pisses me off because I like the car but tired of throwing money at diagnostics only to get the same crap. Mechanics keep trying to re balance, or replace my tires, rotors and brakes. Even when I tell them its been through 3 sets of tires and 2 sets of rotors.

[SnapCoupe]

Originally Posted by vladmury

I was satisfied with the M3 arms but after few months my car developed a nasty vibration that increases with the speed. I actually think the control arms picks up the road imperfection and amplifies the vibration. I am thinking to go back to original arms, the combination bilstein b8+ m3 arms is too hard for normal driving and the NVH has increased.

I noticed this too with the M3 arms and ST coilovers. I road force balanced all 4 wheels/tires, replaced all mounts and bushings when installing my coilovers, and there are no other signs of issues on the front end of the car.

I'm assuming this is just due to the stiff suspension and bushings in the M3 arms, but I have noticed it its worse when the car is cold.

[vladmury]

My plan was to replace them with new arms but it was not a priority since my wife is driving the car and she does not notice anything

[BravoJohny33]

Originally Posted by SnapCoupe

I noticed this too with the M3 arms and ST coilovers. I road force balanced all 4 wheels/tires, replaced all mounts and bushings when installing my coilovers, and there are no other signs of issues on the front end of the car.

I'm assuming this is just due to the stiff suspension and bushings in the M3 arms, but I have noticed it its worse when the car is cold.

Holy crap I have the same problem. When its cold out or the car has sat for a few weeks its way worse than when its warm and the car has been driven often. However, I have new OEM sport control arms. Not M3 control arms.

[BravoJohny33]

Originally Posted by vladmury

My plan was to replace them with new arms but it was not a priority since my wife is driving the car and she does not notice anything

None of the mechanics notice anything wrong either. Its why its pretty much impossible to fix. You really got to get it on the highway at high speeds. If you sit there and look at the passenger seat you will see it shaking back and forth really fast. The cup holder vibrates bad if there is something in it.

[vladmury]

Thats because people who dont drive the car daily cant notice such vibrations. It usually takes a lot of money and parts replaced to find the origin.

I lost fate in the mechanics so I am buying the parts and only tell them what to replace.

Originally Posted by BravoJohny33

You really got to get it on the highway at high speeds. If you sit there and look at the passenger seat you will see it shaking back and forth really fast. The cup holder vibrates bad if there is something in it.

Likely a bad tire or wheel. Road force balance will tell you for sure.

[BravoJohny33]

Originally Posted by FCobra94

Likely a bad tire or wheel. Road force balance will tell you for sure.

Everyone got rid of road force around here. Besides its had 3 sets of tires, 2 sets of rotors, 2 sets of control arms. Still does it. I would hope all of these jack ass mechanics I paid for diagnostic fees and hand me 3000 dollar quotes to replace all my rotors, pads, and tires every time would know for sure if it was a bad wheel or tire.

Originally Posted by BravoJohny33

I would hope all of these jack ass mechanics I paid for diagnostic fees and hand me 3000 dollar quotes to replace all my rotors, pads, and tires every time would know for sure if it was a bad wheel or tire.

lol a shop trying to sell you parts you don't need? Never heard of that happening before <insert sarcasm here>

Yes, those are typical/expected results when you don't ask the right questions. Good luck trying to find the answer to your issue if you're only reliant on bozos to figure it out for you.

Tell me what the road force results were (runout of the wheel, runout of the tire, etc.) and I'll tell you whether or not either is the problem. Without getting that information from the machine/"mechanic", going through the process of road force balancing is worthless when attempting to troubleshoot a problem such as this.

Use this to try and find a shop that can actually help you:
http://www.hunter.com/gsp9700

[BravoJohny33]

Originally Posted by FCobra94

lol a shop trying to sell you parts you don't need? Never heard of that happening before <insert sarcasm here>

Yes, those are typical/expected results when you don't ask the right questions. Good luck trying to find the answer to your issue if you're only reliant on bozos to figure it out for you.

Tell me what the road force results were (runout of the wheel, runout of the tire, etc.) and I'll tell you whether or not either is the problem. Without getting that information from the machine/"mechanic", going through the process of road force balancing is worthless when attempting to troubleshoot a problem such as this.

Use this to try and find a shop that can actually help you:
http://www.hunter.com/gsp9700

So apparently the place I got my tires at upgraded to the road force elite. I have lifetime balance. Will that do a road force balance, match the tires and point out any problems with the wheels? So I need to ask them for a print out or something?

The other thing is it says tires include lifetime spin balance. I am guessing road force elite has a basic mode where they don't match the tires? So they might just use basic mode or something.

Correct...either way, force matching is not required to get the road force numbers; the machine will spit those numbers out even during a "basic" balance. The unit of measure is in pounds.

I've found that any amount of road force over 9 lbs produces a perceptible level of vibration inside the cabin on this platform; the higher the number, the more severe...especially as it comes and goes with speed (meaning, you get vibration/hopping of the wheel/tire assembly at 70 mph but not 75 mph, etc.

[BravoJohny33]

Originally Posted by FCobra94

Correct...either way, force matching is not required to get the road force numbers; the machine will spit those numbers out even during a "basic" balance. The unit of measure is in pounds.

I've found that any amount of road force over 9 lbs produces a perceptible level of vibration inside the cabin on this platform; the higher the number, the more severe...especially as it comes and goes with speed (meaning, you get vibration/hopping of the wheel/tire assembly at 70 mph but not 75 mph, etc.

So what is a good attainable road force number?

Originally Posted by BravoJohny33

So what is a good attainable road force number?

Well, obviously, the lower the better.

If you don't want vibration? 9 or below. I've found that anything more results in vibration/speed dependent "hop."

Some cars are just as, if not more sensitive to road force as ours are (Miata, Corvette, a few Cadillacs, etc. just from what I've seen during research). Most cars don't seem to be as sensitive to road force as ours though. Given that, most road force machines won't "reject" a wheel/tire assembly until it goes over 19+ lbs of road force...so even though you might get a general "passing" grade for any given set of wheels/tires, you'll still feel vibration on this platform.

I've found that Michelins tend to have better QC and therefore have a higher chance of achieving low road force numbers without having to go through multiple tires to find a set that will all output single digit road force values.

Just my $0.02

[BravoJohny33]

Originally Posted by FCobra94

Well, obviously, the lower the better.

If you don't want vibration? 9 or below. I've found that anything more results in vibration/speed dependent "hop."

Some cars are just as, if not more sensitive to road force as ours are (Miata, Corvette, a few Cadillacs, etc. just from what I've seen in my research). Most cars don't seem to be as sensitive to road force as ours though. Given that, most road force machines won't "reject" a wheel/tire assembly until it goes over 19+ lbs of road force...so even though you might get a general "passing" grade for any given set of wheels/tires, you'll still feel vibration on this platform.

I've found that Michelins tend to have better QC and therefore have a higher chance of achieving low road force numbers without having to go through multiple tires to find a set that will all output single digit road force values.

Just my $0.02

Where do you find a tire shop that would bother going through mutiple sets of tires to get a road force balance of 9 if it allows them to sell sets with 19's?

I ordered tires from TireRack...they shipped directly to the installer. The tires that were high road force got shipped back and replacements were sent.

Another time Continental warrantied the tires directly. I must say, as frustrating as it was to go through more than a few tires until I found a proper set, Continental customer service was splendid. After that experience though, I'll likely stick with Michelins from here on out.

[oilcrankinject]

I had the same thing happen my old FWD car. Half shafts were worn out. Once I replaced each side the problem was solved.

[langsbr]

Originally Posted by FCobra94

Well, obviously, the lower the better.

If you don't want vibration? 9 or below. I've found that anything more results in vibration/speed dependent "hop."

Cobra94- how bad would the vibration be above 9lbs? I got some new tires on the front (cheap Achilles which I regret) and they were at 26 and 16 before they indexed them. After indexing they got them to 11 and 13 if I recall. Would that still result in a TERRIBLE vibration? Before the roadforce balance, it was vibrating at 60+, now, it's 80+, but it feels like the dash wants to rattle apart it's so bad. Just want to make sure it's not something else and is just bad tires.

It depends...like you mentioned, the vibration is speed dependent; I've found that the severity of the "hop" goes up with higher road force.

Rotate the tires and see if the vibration follows.

[Gyldenhammer]

Any solution on this vibration issue.-

[Soravia]

Just thinking, were the front under tray aero removed?