I’m hearing a slight suspension “clunk” coming from the front left side whenever I back out of my garage parking space. It almost always happens when I have the brakes slightly pressed and turn the wheel to the left while backing up - and then sometimes again when I unwind the wheel.
I tried to take it to the dealer to have it checked out, but we couldn’t reproduce it when parallel parking.
Has anyone ever had a similar experience, any ideas where to look?
Usually it is the front upper control arms. Check that the bushings are okay with the steering wheel turned all the way to each lock. Then look at the ball joints while someone turns the steering wheel back and forth quickly.
The upper control arm bushings were all replaced last summer. But I’ll have someone help me check the ball joints.
given that its happening in conjunction with turning the wheel both on/off I’d suspect control arms as well.
I doubt its this, but another thing to check is the subframe bolts. I had one fall out in my C5 and it caused the most random clunk; sweeping left hand turns over bumps.
Funny you should post this, as I’m going through this exact thing.
Let me guess - it clunks mostly when you’re near to full lock, and especially in the wet?
I also had my bushings changed recently, as well as the lower arms, and had it checked out again.
The suspension shop told me all the bushings are in perfect shape, and that they’re sure the clunk is actually the wheel ‘skipping.’ This means the issue could be the transfer case, if it’s not allowing the front & rear wheels to move independently (i.e. locking). I’ve driven a car with a locked diff, and yes, actually, it feels pretty similar!
The other day I also noticed the TC light come on when going slowly around a 90* bend. Seems to fit.
I have been advised that a fluid change can usually sort this issue, and I certainly hope so!
In any case, I’ll be heading over to a local ZF specialist - unfortunately you guys in North America won’t have a resources we do here regarding this box, as its used in the Falcon here (and they run 9sec 1/4s with this box!). I plan on having all the fluid changed, and upgrading the box with an oversized valve ‘zip kit’ and possibly a stage 1 clutch upgrade.
Zip kit info-
http://s3.amazonaws.com/sonnax-dev/uploads/valve_body_layout/vbl_file/3/ZF6HP10_26_32_Gen_1.pdf
Trans upgrades-
http://www.cmssydney.com.au/index.php?option=com_content&view=article&id=30
Should this go ahead as planned, and work well, I’ll be sure to share all the info here, and see if its possible to arrange a kit should anyone overseas want one.
-P
As the others mentioned check the control arms under that situation they would be overly stressed. It could be the lower control arms. It’s best to pull the car on a hoist and look at the suspension. Did the dealer put the car up or just road test it
[quote]Let me guess - it clunks mostly when you’re near to full lock, and especially in the wet?
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That sounds like it, but it seems to happen wet or dry in the parking garage, occasionally on the street.
[quote]The suspension shop told me all the bushings are in perfect shape, and that they’re sure the clunk is actually the wheel ‘skipping.’ This means the issue could be the transfer case, if it’s not allowing the front & rear wheels to move independently (i.e. locking).
[/quote]
You’re talking about a transmission fluid change to fix the problem, right? Let me know how it goes, I may do the same when I have the car scheduled for some work.
And I’ll have the lower control arms checked as well, since the car was only road tested. Is this a safety issue or only an annoyance?
Could be a safety issue but it’s hard to tell just from a small description. Before anyone changes the fluid try checking the level first. The fluid could be on the low side and that would cause this issue. Changing the fluid would cover up the car not having enough fluid if that was the case.
Keeping the wheels straight, move forward, apply brakes and come to a full stop. Keeping the wheels straight, put the car into reverse and then hit the brakes.
Do you hear the clunk then?
Put the car in gear and move forward and apply the brakes again. Does it clunk?
I had an issue on my B8 S4 with the stock floating caliper in which the carrier bushing had becomes soft enough that it allowed the caliper to move if that makes sense.
Not sure if that’s the culprit here (or if you even have a floating caliper). Just trying to contribute. 
My car is going in on Tuesday.
I’ll make sure to ask them to check the level before draining, so we have that info.
I can say that it really does feel like a loose arm/bushing. But the place I had it checked out at I have been going to for years, they only do suspensions, and I trust them when they say the bushes were all fine.
The reason why it makes sense that it could be bushes in that situation is because when you are at or near full lock, the two front tyres are not in parallel. So, they bind when you do a tight circle. A loose bushing will show itself in this situation as it will allow the movement.
I have a slight DTV on the front left, which is also the clunky wheel. At slow to mid speed braking, I get a thunk in time with the DTV.
Anyways, all just speculation, and maybe we don’t even have the same issue (though it’s doubtful!). I’ll report back.
Not for me. No clunk until I turn the wheel.
i was gonna say check the brakes as well. Floating caliper. Im moving on from control arms because he said they were replaced recently. ALSO. Does this model have anti rattle clips like the B7 s4? If so it could be those if they happen to have anti rattle clips.
This clunk happens when control arms are going bad upper and/or lower, also there was a service bulletin on the bushings and bushing grease that makes a noise similar other this. Also the bushings make noise in extreme weather.
When does this happen temp wise?
I haven’t noticed any difference between summer/winter. Garage is 2 floors down, maybe 18-20C now going into summer.
What suspension components have been replaced and at what nileage vs now?
I have a little clunk in the front passenger side when it’s hot out. I didn’t notice it at all during the colder months. I’m pretty positive it’s my UCAs and the bushing is just stiffer when it’s cold and doesn’t allow the extra play.
I finally got my car on a lift for new pads & rotors. All the control arms/bushings looked fine and we were finally able to hear the ‘clunk’ when we backed the car away from the lift. My mechanic is convinced the sound is coming from the brake assembly. Apparently there is a TSB on this, and it’s not a problem. It only seems to happen during parking maneuvers so I guess I can accept that.
But does anyone have more details on this TSB?
I’m convinced that the sound is coming from my steering rack - usually when I am turning the wheel a fair amount with the brakes applied. This seems to be the case when parking. Does anyone have any experience with inspecting steering racks?
Mine did this their was a TSB which I never pursed where they used different grease I believe on the control arms or some other part of the suspension. It only happen to me on full lock scenarios driving slow and typically when cold and it wasn’t worth me investigating. If it’s killing you yeah check out the steering rack but I’m not convinced that’s the problem given similar symptoms mine had?
Have you checked the steering rack bolts? There is one on each side as I recall, but I had one loose UNDER the battery tray that caused a clunk at low speed when turning from side to side. Worth checking out as it’s pretty easy to do.