[200q20v] Susension bushings
Derek Pulvino
dpulvino at agraus.com
Sun Apr 22 05:04:48 EDT 2001
Greg,
(Chris, may want to include this in your site for others reference, although my ear to the list makes me feel I'm pretty isolated in this matter)
Ha, ha, just kidding about that first message. In reference to your suspension bushing question, the Scott Mockry site is a good reference for parts. Recently rebuilt the front end of my car. So far I'm kind of frustrated in that after all that work the car still does not drive like it did when I first got it. I replaced subframe bushings, inner control arm and all sway bar bushings, outer ball joint ends, strut bearings, and the struts. The information from my experience that I didn't get from the list, is that this might not work.
I have several theories, but because of time and money limitations, haven't been able to trace them down. I think these cars are pretty sensitive to fine tuning. Run a google search for alignements and balljoints to see what I mean. Ideas are incorrectly aligned subframe, bad alignment, worn ball joints or inner tie rod bushings, worn steering damper, poor quality parts, or maybe I put something together wrong.
My car will be expertly aligned in the next couple of weeks, and at that time I can get the subframe properly aligned. Maybe this will help, and damn I hope so.
Just wanted to let you know of my experience before you jump in; hopefully you can join the others on the list with rebuilt front ends that came together like salt and pepper.
If you have any other specific questions, I'd be happy to help. I want to figure this out and maybe somebody else's parallel experience can help.
Derek Pulvino
PS: Heres some communicatin I had with Scott Mockry on the subject.
Derek,
I have noticed the 200 and S4 quattros seem to be susceptible to this
problem. There are a few things that contribute to excessive wandering when
hitting ruts in the road. Wider wheels with high performance low profile
tires with stiff side walls, aftermarket wheels with a different offset,
toe out, excessive negative camber, defective steering damper, loose
steering rack pre-load, play in the inner tie rod end rubber bushings,
loose upper strut mounts, torn lower control arm bushings, loose sway bar
bushings etc.
The front camber spec allows 0 to -1 degree, setting it closer to 0 should
help somewhat. The rear is spec'ed to be 0 to -0.5 degree. The car should
get a 4 wheel alignment, as the rear settings can steer the car. The camber
and toe settings from side to side should be adjusted to be the same, and
not just within specs. If the car is using stock springs, then you should
be able to get the camber close to the positive end of these camber specs.
Cars using aftermarket springs and have been lowered often times will have
excessive negative camber and won't come close to the 0 camber settings.
If the camber is not equal from side to side and can not be adjusted
equally, then the subframe position should be adjusted to equalize this
camber setting. If the front suspension is apart, a plumb bob and string
can be dropped from the upper strut mounting hole to measure the side to
side difference to the lower control arm bushing center point, and then the
subframe bolts can be loosened and then the subframe moved side to side to
equalize this as much as possible.
I assume you torqued down the retention bolts for the sway bar front
bushings and the end link bushings and lower control arm bushings when the
car was sitting on the ground with the suspension settled? This prevents
putting the bushings in a bind when the front end is up in the air.
My 87 5000TQ track car runs -2.5 degrees camber in the front and -2.0 in
the rear, and has about 1/8 inch toe out, and has 16X8 S4 wheels with Kuhmo
track tires, this thing "leaps" violently to one side when encountering
ruts in the road.
HTH
Scott
>Rumor has it you don't have much time these days for answering questions,
>but figured I'd give it a shot anyways. My car is 91 200tq with 141k miles
>on it now. I recently did a front end rebuild consisting of replacing the
>tie-rod ends, all control arm and sway bar bushings, subframe bushings,
>trans mounts, struts/shocks, and strut bearings. I've had the car aligned,
>but unfortunately had difficulty getting the shop to bring it to factory
>spes; of main concern here is toe being set at a total toe of 0.08, about
>half of the prescribed factory value.
>
>The main question is though, after all of that the car did loose the brake
>shimmy, but still has a front end wander. It likes to track grooves on the
>freeway, and doesn't hold a the corner line once it's dialed in.
>
>Potential problems I see at this point are maybe wear in the steering rack,
>slightly worn ball joints, incorrect alignment, or maybe the steering rack
>damper. Didn't notice slop in the ball joints when out, and I've got the
>rack pre-load pretty well dialed in. Another alignment shop I went to
>thought maybe something didn't go together right upon reassembly, but I
>can't think of where that might have occured. Had the Bentley pages on
>hand, and dialed into the factory torque specs. They thought maybe
>misplaced washes or the like on the front strut reassembly; haven't noted
>any "coil bindings."
>
>I remember how the car drove when I first got it, and after all this it's
>not back there again. Any suggestions on where to look at this point, and
>maybe just how sensitive the car is to being set to the proper alignment
>specs. Don't want to give up here, but at the same time don't want to spend
>more time in a hunt and peck manner.
>
>Any input you may have would be appreciated.
>
>Derek Pulvino
Derek,
> Have you seen much come up in the way of ball-joint problems? If the ball-joints were worn, would play be seen with hand pressure, or does the compliance of a worn ball-joint only become observable with more force, ie while attached to the car and using a pry-bar?
Normally if the ball joint is tight with the control arm off the vehicle, then they are ok. Most of the ones I have seen with 100-140k miles are still tight, it is only the ones that have had torn grease boots that show up as very loose when they are removed. You can also put a jack under the hub to take off the coil spring tension and then carefully pry the control arm/ball joint up/down to see if there is any play. Usually when the ball joints are really worn you can hear some clunking when going
over speed bumps/pot holes.
> Another thing, when you mention the inner tie-rod end bushings, is that another replacement part, or something that can be tightened down? I assume you're refering to the point where the tie-rod is attached to the steering rack.
I believe the entire tie rod would have to be replaced, I don't think these bushing are available separately. If the car handled ok before you did the suspension work, then this is not likely the cause of the problem.
> As far as alignment settings, aren't we dealing with a balance sheet type situation here? With more negative camber isn't grip somewhat increased, and doesn't more toe-out give sharper steering response at the expense of straight line stability?
Yes, more toe out gives a better turn in response, as the expense of the car wandering when driven straight down the road.
> Wasn't aware that camber settings could effect straight line stability, but not really surprised to hear that.
I am mostly referring to the reaction when driving over a groove in the pavement or driving over uneven pavement in the road. We get a lot grooves in our roads here due to studded tires, and when the car has a lot of negative camber and stiff performance tires, it tends to jump to one side when encountering the groove.
> My car is currently setup with camber at -0.63 on both sides of the vehicle, and total toe at 0.08 (or maybe -0.08, whichever is a toe-in setting). I don't think the subframe is centered though, since the positioning of the bolts on the upper camber plates is not a mirror image from one side to the other, so to go more positive might take a little extra finagling. I guess it would be possible to move the camber to a more positive setting on both sides, but what would I see lost in the process?
You may want to take a look at the caster readings from your alignment, uneven caster can make the car pull to one side. Even though the caster is not specifically "adjustable", moving the subframe around can change this somewhat as the front stabilizer bar tends to locate the lower end of the strut/hub and determines the caster.
> With the back, I did have a four wheel alignment done after all the work was completed, and though I don't know what numbers where, they did not raise any cause for alarm.
Too much toe out or unbalanced toe, could cause the rear end to steer the car. Uneven camber would also be a concern at the rear.
HTH
Scott
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