Suspension issue .....I knew I was only scratching the surface....!

[Joelchester]

So, had the control arms done in her, however, upon braking from motorway speeds (70mph) the front end goes into what can only be described as a DEATH WOBBLE ! Could only just hold onto the wheel, and was difficult to even see....think earthquake !....any ideas ? Yes it does need the tracking doing, and am doing that next week when I have new tyres fitted ,but it wasn’t doing this with the ‘old’ control arms on, even though they were fecked....weirdness ?....


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[TxGR8White]

Did you do both upper and lower control arms?
Were the upper arms pre-loaded and torqued properly?

[Joelchester]

Did you do both upper and lower control arms?
Were the upper arms pre-loaded and torqued properly?

Not sure, to be honest...the front wheels had loads of ‘front to back’ on em (brake then reverse).....moved about 6 inches.....that’s fixed,but this death shake is scary.....just wondered if anyone had any ideas....feels like something ain’t been put back....


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[TxGR8White]

the problem is most people only replace the uppers (because they are about 1/4 of the price of lowers), but if the lowers are shot, then you will prematurely destroy your new uppers in no time. First thing I would do is verify what was actually replaced. Next, I would check if the uppers were done properly. That should solve your problem.

[Joelchester]

Cheers will check, I did mention about the ‘under load’ torquing to him, which he already knew about.


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[8Tech]

Check that the caliper pistons are all free. The 840 inner pistons are a regular seizure item and the resultant bending of the disc by forcing the outer pistons against the disc rather than gripping the disc is as often to blame as the upper arms, possibly more often.

If you check the back face of the discs, you may find they are using a lot less of the braking surface than the front face.

In this case, you will need to repair or replace the calipers and replace discs and pads.

[Dr. T]

Weird that it does it right after replacing the control arms. Were the bushings installed with the correct orientation? Properly torqued with the full weight of the car? (I’ve seen where they just slightly lower it down on a stand)

Also recheck air pressure in front tires and previous wear patterns may exaggerate the wobble and re-mount front wheels...


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[Joelchester]

Weird that it does it right after replacing the control arms. Were the bushings installed with the correct orientation? Properly torqued with the full weight of the car? (I’ve seen where they just slightly lower it down on a stand)

Also recheck air pressure in front tires and previous wear patterns may exaggerate the wobble and re-mount front wheels...


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He’s chucking one of these on it...fingers crossed !....



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[Dr. T]

Yeah forgot to mention the idler arm bushing...

Coincidentally, mines doing the wobble thing again too, but it seems like it’s only from the front right ....a quick inspection revealed the boot partially off/busted sway-bar link.

Can a broken sway-bar link cause a wobble?

[Joe850V12]

I dont think so, I've done most of the front suspension, I havent gotten to the swaybar ends yet, one is very loose. Its on the winter list.
I have shaking on even abnormal sway, it goes thru a traffic circle just fine

[kiwiCSi]

Had a similar, very severe shimmy on an E34 once, which was eventually tracked down to bad tyres.
First suspects of course were brake discs, suspension bushings and linkages but none of these were overly worn.
It turned out that two unevenly worn and imbalanced front tyres proved to be the culprit.
Replaced both tyres and the problem went away.

[rjbaren]

Regarding sway bar links. Both of mine were bent and there was no hint of vibration. I replaced them both. There was no difference in driving characteristics before or after replacement.

[mbarrett635]

Regarding sway bar links. Both of mine were bent and there was no hint of vibration. I replaced them both. There was no difference in driving characteristics before or after replacement.

On the other hand, I had a bent sway bar link, and it resulted in a mild wobble, but a horrible 'clunk' every time I went over a bump.

Mike Barrett

[vgs]

Had a similar, very severe shimmy on an E34 once, which was eventually tracked down to bad tyres.
It turned out that two unevenly worn and imbalanced front tyres proved to be the culprit.
Replaced both tyres and the problem went away.

I had a moderate shimmy when I first bought and picked up my 8er this April.
It would happen at 80km/h. Below 70km/h and above 90km/h it would be fine.

As I drove it home, about 350km into the 1,300km trip, the shimmy got worse until a rear tire blew. I changed it to the spare and diverted to San Antonio, TX to get all four new tires.

I had checked the date on the tires and they weren't old. The tread was almost intact and not dry at all.
I think the problem was that the car had just hadn't been used enough before I bought it and the tires deformed.

With the new tires all kinds of shimmy completely dissappeared. Smooth as silk.

IMG_2028.jpg

[rjbaren]

I also have a 5 series and when I bought it last year it drove around town just fine. Terrible shake/vibration above 60. Got the tires balanced but no difference. Then I bought a cheap set of wheels and mounted snow tires on Craigslist and then it was smooth as silk. I have since bought a new set of all season tires on the original wheels and again, it is smooth as silk. Smoother than the winter tires too.