B6 Cabriolet Knocking sound on semi lock (Left and Right Turn)

[DrStrange]

Hi guys.

Something i had for a while and thought I would ask for advice.

When i purchase my cabbie, I had OEM 17's on them. As you may know, made a silly mistake and purchase replica 20's which weighed a ton. They have surely ruined my suspension and ancillaries but this is purely anecdotal as im no expert and wouldnt really know what to look for apart from the obvious.

I now have 19'' OEM RS5 Peelers and they are fantastic. However, ever since having the 20's I feel they have taken a toll on my suspension and ride set-up.

So, as a result, im getting the classic 'knocking' noise when I turn in both directions. My steering wheel doesnt have to fully lock for this to happen.

Any ideas what this is exactly? (Ive searched lots of forums and do have an answer but would also like you guys and girls input )

Dan.

PS. I plan to Powerflex polly bush and install AP adjustable coilovers on my car soon for extra info)

 

[Jonni3]

Anti Roll Bar Link Bush's ?

 

[mattmanwrx]

Top mounts? Happened on a Peugeot I had, and on lock would knock or "spring" once in a while. Don't know how wheels would do that though.
PS, I'm no mechanic, and I don't know what I'm talking about. I'm just guessing.

 

[DrStrange]

Thanks a lot guys for the response. Much appreciated (been ill all of last week)

It just feels as if all this swapping around for different wheel set ups have taken its toll on my suspension.

There are also high pitched squeals which seems to come from the suspension when I go over even the most minor road imperfection and reckon the bushes are knackered, hence why im going to upgrade everthing and hope it all goes away.

Really want to sharpen up the boat like handling of the cab.

 

[DieselJake]

Good stuff, mine's been bad for a while too so I think I'm going to do the same.

Any links to the polybushes/control arm kit your going for? Been searching for a while but haven't been able to find any b6 polybushes other than the roll bar one's.

 

[DrStrange]

Thanks!

Definitely seems like the way forward.

I Live in London and their is a local VAG garage named 'VagTek' who are PowerFlex dealers so am gonna go with them.

Im currently requesting a quote but all depends on what needs to be done. Front is 100% confirmed. Back - not sure yet if it needs to be done.

As far as I know, powerflex do bushes for almost any car including ours.

Im not replacing the control arms so am hoping its nothing to do with this component.

Will let you know ALL details when i get the quote etc.

 

[Pops848]

My bet would be top mounts or CV joints depending on the following

Constant clicking / banging when steering in either direction, then I'd put my money on CV joint

If it knocks or bangs once, maybe twice then it would be top mount

This is because..

CV joints are constant velocity, so as you turn it manouvers and if it's fubard then it will constantly knock

Top mount houses your spring, as you turn the spring will wiggle, if it can't get into place it'll go under tension, eventually "springing" out and into place, hence the single knock

That's my guess

 

[DrStrange]

Thanks A lot for the detailed help Pops. Interesting.

I must confess I know little about suspension but the consensus is saying Top mounts and CV Joints. After having a good read about both, you guys are correct, it would appear to be one or the other or in fact both.

Hopefully when the AP coilovers come on, the situation will be remedied but will also look into new CV joints.

Is it worth buying new from TPS or aftermarket or even Ebay 2nd hand?

Dan

 

[karltea]

CV joints go allot on s4's, jack it up off the floor and turn the road wheel and see if there is any play, also grab the drive shaft and give it a twist and check for any play. If they are really bad you will get a vibration on the steering wheel almost like having a puncture, with mine this happened at about 50mph

 

[DrStrange]

Thanks Karl for the advice.

Im hoping it aint as bad as that but will check with my mechanic as he has my car at the moment.

 

[karltea]

cv joints are easy to do, take off wheel. take off ali heat shield thats around the inner cv (7mm hex? and use a impact as they round off easy) then triple square spline to take off half dozen bolts that hold the inner cv on (dont use a normal spline or star/torx as this will slip out and round of the insides) . turn the steering wheel full lock and the outer cv should pull out

 

[Pops848]

Thanks Karl for the advice.

Im hoping it aint as bad as that but will check with my mechanic as he has my car at the moment.

Hope the coilies fix it mate!

If not, and you need CV joints then make sure you do your research, during the 02/03 changeover the A4 went from grooved CV joints to smooth CV joints, the difficulty is that the cabriolet seems to be updated prior to the saloon, so you might already have the updated CV joints that are a lot cheaper than their earlier versions.
If you need them, speak to your mechanic and ask to check if they are smooth bore or grooved bore, and then get them at ECP on a discount weekend.

The only other thing that it can possibly be is control arms, these are metal bars with rubber bushes, usually these squeak and get annoying more than bang though

 

[QuattroCalum]

My bet would be top mounts or CV joints depending on the following

Constant clicking / banging when steering in either direction, then I'd put my money on CV joint

If it knocks or bangs once, maybe twice then it would be top mount

This is because..

CV joints are constant velocity, so as you turn it manouvers and if it's fubard then it will constantly knock

Top mount houses your spring, as you turn the spring will wiggle, if it can't get into place it'll go under tension, eventually "springing" out and into place, hence the single knock

That's my guess

The suspension and steering are separate actions on the A4, the strut remains in position with no turning forces on it at all. The steering forces are all on the upper and lower control arms and the hub carrier. The hub carrier essentially pivots round the suspension strut, have a look on this diagram

http://i24.photobucket.com/albums/c47/darrbar/Car stuff/CIMG1354.jpg

 

[DrStrange]

Thank you guys for the info. All noted.

Hope the new Coilovers will what ive reported. If not, without even checking, im pretty sure you would all appear to be right and its the CV joint as being the culprit.

Getting the car back V soon so will update as and when.