[thomth]

In January this year all of the brake rotors and pads were replaced. Also the rear shocks. After 3000km there’s suddenly a vibration with above 40mph that worsens with braking

2 weeks ago the inner and outer tierod, 3 of 4 control arms were replaced. And also the shocks, mounts. The mechanic let 1 control arm
In place, the thrust arm. He said it looks good en he couldn’t the bolts loose. As far as I know it’s original.

I still have the same vibration. A little bit less intense than before. But still present. Front wheels were balanced, car was aligned. On an other set of front wheels the vibration is still present. The brake rotors look fine, no heating. No noise with braking

My first thought is that the last thrust arm should be replaced. But is there anything else to look at? Maybe the brakes? Bearings? Rear wheels that cause a vibration in the steering wheel?

[Runnin'Rich]

Some options:

1) replace parts until noise is gone
2) run car in gear on axle stands and listen to parts with a mechanics stethoscope(death & injury possible)
3) buy a ‘chassis ear’ and listen to the vibrations of different parts via radio while driving

[gaze2]

The vibration you feel in the steering wheel yes?
Does the vibration go away above ~65 mph? then its probably tire balance
Otherwise my bet is on bad control arm bushing that leads to change in the suspensions geometry (alignment) at speeds and under load (braking), leading to vibration. I had the same issue with my e91, replaced disks, tie rods, and in the end new control arms fixed the issue.

[thomth]

Yes, feeling stays above 65mph so I’m guessing it’s the thrust arm

[gaze2]

Before replacing my arms I had a lot of suspension play that I could test by turning the wheel to one side and kicking the tire on the threads side (radially). Swapping out the new arms the movement is significantly less. You could try that, but its so weird that a mechanic couldn't get the bolt loose. If its the bolt on the hub and he tried loosening it and it seized or something and retightened it I would suspect the ball joint is dead. If its subframe side, then I honestly don't know how he couldn't get it loose. I had to use an angle grinder to get the thrust arm to hub ball joint connection off, the little nut wouldnt let go even when cut in half, had to dismember it into 3 pieces....

[Jaronbwall]

thomth How many miles on the car? Sounds like a suspension related issue. If it's not it can also be a bad tire(s). Belts inside the tire fail when subjected to impacts (potholes) and it really throws off the balance at speed. I had a similar vibration issue a few years ago, replaced/upgraded stuff, but the big issue was bad tires. After installing new Indy 500 tires 98% of the vibration went away. I'm at 125k miles so it's never going to be perfect anymore.

[thomth]

Car has 147000miles driven (235000km).

Tires are new, replaced them. Also, the vibration is still there on other front tires. I haven’t tried other rear wheels but I can imagine that warped rear tires can’t induce a vibrating steering wheel?

All of the parts of the front suspension are replaced. Exept one thrust arm. First thing to do is replace that one I think

[thomth]

Could it also be the bearing of the cardan shaft? Heard it before

[Tambohamilton]

"arm looks fine" is a classic post-justification for a stuck bolt. If the bolt wasn't stuck, you can guarantee the arm should be replaced. The bolt being stuck doesn't magically mean the arm isn't worn out. IMO you should find a competent (or at least honest) mechanic to replace the last arms.

[whyzee125]

99.9% of the time there's a steering wheel either in the seat or the steering wheel, it's wheel/tire related. Many tires can "balance fine" but have major vibrations. I'd look closely there first, though if you paid for 4 control arms, I'd make sure all 4 get replaced. Seems silly to leave 1 especially since he just couldn't get the bolt out. The bolts absolutely should be replaced anyway so why didn't he just cut it and replace?

[thomth]

The last arm is replaced. Vibration at 60mph is gone, but still there when braking.

So I suspect I have a warped rotor. Although they are 6 months old… all ATE. So where to look? Production fault, wrong placement ?

[gaze2]

Have you been to an alignment recently? Could be that.

[Tambohamilton]

Originally Posted by gaze2

Have you been to an alignment recently? Could be that.

No, bad alignment won't cause vibration.

[thomth]

Yes it’s been aligned

When braking the car isn’t pulling to the left or right. So i don’t think it’s the caliper. Maybe just bad luck and a production fault in the rotor…

[rvphuerta]

Originally Posted by thomth

The last arm is replaced. Vibration at 60mph is gone, but still there when braking.

So I suspect I have a warped rotor. Although they are 6 months old… all ATE. So where to look? Production fault, wrong placement ?

Did you clean the hub surface and calipers guide pins?