Balancing or other?

Hi,
I have a 1990 (H) 535i Sport.
When the tyres got way beyond illegal on the original metrics, I ditched them for 17s (235 45 17). Around this time I started getting a bit of a
wobble around 60MPH.
Being as Sunday was my only free day had to take it to Kwik Fit to get the wheels balanced. Problem was still there.
Became quite obvious that they had done nothing at all, so took it back. This time I stayed. So actually saw them carry it out. However, still no better.
Got the tracking checked (not that I was expecting this to be the problem), but all OK.
Come MOT, explained the problem, but they found nothing wrong with steering or suspension.
Despite being a bit annoying, it was "livable", and went through a further 3 MOTs with no problems found. Infact, other than the odd bulb or low brake pads, it never had any problems.
Recently changed the tyres on the front. Wasn't overly impressed with the place that did it. Over an hour and a half to change two tyres!?!?
However, now it seems to be a whole lot worse. Still only happens around 60MPH, but shakes quite violently during this small speed range.
Now commen sense still seems to shout "BALANCING", but I have also noticed a bit of movement in thesteering wheel when car is stopped and engine running. It is hard to see, but it looks like the movement may be within the coupling in the (pardon the un-technical term) steering "rod" underneath the exhaust manifold.
I am assuming that this would be a ruber donut coupling, similar to one I previuosly repaced on a 3 series?
Is this slight movement normal? I can't say that I particularly notice any play when driving, but it may just be less noticable with the power steering pump running.
Would this give the kind of symptoms described?
Many thanks, Simon
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Your old tyres had more sidewall, this masked the problem.

Your worm and sector steering will have a fair bit of play in the straight ahead position, it's not the problem.
The problem is that E34s weren't really designed for such low profile tyres. Unless your tie rods, centre drag link and control arm bushings are in top condition it'll shake. I bet it's worse under hard braking. My first move would be to replace the centre drag link.
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JoshIII comments: Check the rotors for unbalance.
If the rotors aren't balanced, then balancing the tires won't help.
I remember when they had a system that would spin wheels up and balance them while mounted on the car (vintage 1964-1973). This was just before computer balancing was developed.
Problem with this on-the-car system was, they had to attach a device to the tire that was being balanced. The device itself could be slightly out of balance or not mounted correctly, which made the whole process futile sometimes. A system like this, if perfected, would correct an unbalanced rotor as well.
Also, make sure the tires are dynamically (computer) balanced, not just statically. The inside *and* outside of the tire needs to be balanced separately, i.e. dynamically balanced.
The problem I have with my old 1980 vintage BMW, are the wheel balance weights have to be carefully chosen from the shop's assortment to conform perfectly with the aluminum wheel rim, else they will fly off within days. I nearly always have to pick the type of weights for the technician to use myself.
Tire balancing is still both a science and art!
Good luck!
JoshIII upstate south carolina josh3i at hotmail . com
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"Rotors"??? Discs? Hubs? Sorry, not quite sure to what you are referring.

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SilentBob wrote:

en-us "rotors"->en-gb "brake discs"
Andrew
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SilentBob wrote:

I can almost guarantee the control arm bushings are gone. These are a common replacement item. Change them out and you will have solved your shake.
Cheers, Bob
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Ok, so both John & yourself have suggested control arm bushings. Do you have a link to a diagram of this? Unfortunatly the BMW parts & repairs discs that I have no longer work. :(
Sorry. I'm not a mechanic. Given a diagram & instructions I can usually do the work required though.
Is this a fairly simple job? Or cheap, if given to a garage?
Thanks, Simon
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JoshIII suggests: The simplest way to check for slack in the suspension linkages is have someone drive the the car for you very slowly in a parking lot or flat pavement. While at the same time you walk along beside the front wheel.
Have them apply or impulse the brakes, while watching closely the hub of the wheel to see if it deflects backwards when the brakes are applied.
If the front wheels deflect only 1/8 of an inch when the brakes are applied, you're bushings are tight and OK.
If the front wheels deflect 1/2 inch or more when the brakes are applied, its time to check bushings in control arm and ball joints etc.
Good luck!
JoshIII josh3i at hotmail . com upstate south carolina

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Try realoem.com: http://www.realoem.com/bmw/showparts.do?model=HD12&mospidG382&btnr1_0250&hg1&fg  for a diagram. The lower control arm (and ball joint) is #7, and the unlabelled one that #15 attaches to the wheel support assembly.
The parts are at http://www.pelicanparts.com/bmw/catalog/shopcart/BE34/POR_BE34_SUSshk_pg4.htm#item19

Well, it's simple, but requires a couple of specialized tools (spring compressor, pickle fork or whatever to remove the arms, etc. There are ways to replace the pressed-in ball joints (cheaper), but you have to remove the control arms anyway...
FloydR
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SilentBob wrote:

The arms that go from the chassis to the bottom of the wheel hub. I had mine done, it fixed a chronic problem similar to yours. It was just 'fussy' about the wheels and tyres before that. Not an expensive job. 40 quid a side I think. Usually easiest to replace the arms with new ones c/w new bushings.
It's normal to have play in the steering box. Unfortunately that just seems to exacerbate any problems like this. You could try changing the power steering fluid, it improved my E39, but the E34 is a different box so I don't know. It has an adjusting screw but that just makes the steering stiff. It might take out some play but I turned mine back after a few weeks because I hated it.
The play will seem much worse with the engine off.
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Would any of these suggested faults be an MOT failure?
The car has been through 4 MOTs with the problem, and I have even described the problem prior to the MOT. However, they have never found a problem with steering/suspension.
Is it possible that it could just be very poor balancing from the school leavers at the fast fit centres?
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Big snag for an MOT tester is that some of these joints had have a degree of compliance built in, so the standard lever test will show some movement even on a perfect one.

It usually turns out to be control arm problems.
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