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Knocking when approaching full steering lock.....

Posted: Thu Dec 03, 2009 1:37 pm
by bye bye
Hi,

Last night I noticed a slight knocking when I approached full lock (both ways) when manouvering.

I did a search on the site but nothing came up, however I am sure I read something previously which was similar to this.

Steering rack?

Cheers


Mark

RE: Knocking when approaching full steering lock.....

Posted: Thu Dec 03, 2009 1:56 pm
by henryhale2704
You are right, there are numerous threads on this site (e.g. http://www.rs246.com/index.php?name=PNp ... k+knocking).

Ultimately it's not an issue.

Re: RE: Knocking when approaching full steering lock.....

Posted: Thu Dec 03, 2009 3:47 pm
by bye bye
henryhale2704 wrote:You are right, there are numerous threads on this site (e.g. http://www.rs246.com/index.php?name=PNp ... k+knocking).

Ultimately it's not an issue.
This is not the issue I am having. Re-read my post...I don't think I mentioned dragging or vibration.

RE: Re: RE: Knocking when approaching full steering lock....

Posted: Thu Dec 03, 2009 3:53 pm
by henryhale2704
Apologies, I assumed that the "slight knocking" could equate to the "vibration" that the linked article spoke about. Maybe this thread describes the issue you are having ( http://www.rs246.com/index.php?name=PNp ... t=knocking ).

Re: RE: Re: RE: Knocking when approaching full steering lock

Posted: Thu Dec 03, 2009 4:39 pm
by bye bye
henryhale2704 wrote:Apologies, I assumed that the "slight knocking" could equate to the "vibration" that the linked article spoke about. Maybe this thread describes the issue you are having ( http://www.rs246.com/index.php?name=PNp ... t=knocking ).
That's it...thanks.

RE: Re: RE: Knocking when approaching full steering lock....

Posted: Thu Dec 03, 2009 4:40 pm
by pad125
I've read the posts above and followed the link, I'm I right in thinking that the noise we're talking about sounds like bolts sheering off or the wheels about to fall off?

RE: Re: RE: Knocking when approaching full steering lock....

Posted: Thu Dec 03, 2009 5:41 pm
by sonny
I experienced the knocking sound too on turning left. I had Audi give the car a pre-track inspection and they discovered the steering rack was to blame for the knocking, took all of about 10 seconds to tighten the bolt, I also noticed that the car was more planted at high speeds.

RE: Re: RE: Knocking when approaching full steering lock....

Posted: Thu Dec 03, 2009 6:25 pm
by lengster1
Mine when manouvering at near full lock makes wheel hop or jump as if theyre both not pointing in the same direction when on full lock,its done it more since it had a new lower suspension arm fitted,i was told no point tracking it as my front tyres were over half worn, which i cant get my head round!!!!! To me when anything is replaced in the steering system it needs geometry checking regardless of tyre tread depth,when the suspension arm went it made a massive bang on nearly full lock every now and then

Re: RE: Re: RE: Knocking when approaching full steering lock

Posted: Thu Dec 03, 2009 7:04 pm
by PetrolDave
lengster1 wrote:as if theyre both not pointing in the same direction when on full lock,
They're not, and they're not supposed to!

The wheel on the inside of the turn has to follow a much tighter circle than the wheel on the outside - so the wheels MUST point in different directions.

http://en.wikipedia.org/wiki/Ackermann_ ... g_geometry

RE: Re: RE: Re: RE: Knocking when approaching full steering

Posted: Thu Dec 03, 2009 11:02 pm
by lengster1
Fully aware of that,but to the degree were the outside wheel is jumping and skipping while manouvering? Does anyones elses do it? Is it the general set up of the car? Firm sidewalls on michelins? I never had a car do it to this degree.

Posted: Fri Dec 04, 2009 1:18 am
by Angelo_Amato
i think audi would call it a 'characteristic' of the multi-link syspension.

My boss's A4 s-line TDI did the same and occasionally my 1998 Passat 1.8T did it as i pulled off my drive.

When you see the movement the multi-like suspension has to go through, you can sort of understand the odd 'groan' but still not pleasing.

Having replace these on my other Passat, they do get alot of stick.

the B5 platform was highly critisied for the arms failing (creaking loudly :P)but surprise,surprise, VW/Audi refused to recall (prob due to the large number of cars it affected!)

Re: RE: Re: RE: Re: RE: Knocking when approaching full steer

Posted: Fri Dec 04, 2009 3:22 pm
by PetrolDave
lengster1 wrote:Fully aware of that,but to the degree were the outside wheel is jumping and skipping while manouvering? Does anyones elses do it? Is it the general set up of the car? Firm sidewalls on michelins? I never had a car do it to this degree.
With both of my S4s and with my RS4 in cold weather I experience the tyre "jumping" on full lock - with Dunlops, Michelins, Pirellis and Goodyears - there's a large contact patch which is being twisted as you turn and something has to "give", so the blocks on the tyre jump since they're cold and stiff.

knocking on steering

Posted: Sat Dec 05, 2009 9:24 pm
by hungryhorses
i had a knocking on my steering left and right side not even at full lock.

Took it to the dealer West london Audi as still under warranty, they tightened a bolt - and all was well for a few months after which the knocking came back.
Took it back and they tightended bolt again and they wrongly reckoned it was the suspension.

Third or 4th time i returned - they kept the car for a few days and decided to change the whole steering rack (1 month short of the warranty running out).
All has been well since and steering tighter.
hope this tale helps.

Posted: Sat Dec 12, 2009 1:02 am
by iluvmercs
I had a problem very similar to what the OP describes.

It turned out to be something wrong with the front suspension arm.
It was replaced under warranty within a couple of days.

I've now got the problem occurring on the other side, so it will be going in again very soon :)

Darren

Posted: Sat Dec 12, 2009 3:38 am
by ArthurPE
several things are happening in that scenario:
-the CV joints are at the end of their range, some binding is natural
-the tires are scrubbing due to turning angle differance, causing some suspension binding/hopping/knocking, forces are applied/relieved
-the diffs are interferring, front side to side and the rear is 'pushing' the front, loading the front suspension and drivetrain
-slip in the front diff, as much as 25% is reaching its limit and binding the diff...
-the inside wheel is turning much less than the outter, the diff senses 'slip' and starts moving torque side to side...
-the steering is hydraulic, at the extreme range it 'stalls' and the pressure builds up and oscillates as the PR valave relieves it (pulsing)

these system(s) are designed and calibrated over a certain range, and they try to keep that as narrow as possible for the best response in the normal operating range (at speed, on the road, not slow/parking, etc.), at the limits the system(s) lose some fildelity and become less stable (the diffs, hydraulics), it's a sophisticated control system, and 'lose' a bit of control, or control less accurately

my car does it at full lock, I don't consider it an issue, I just avoid full lock

it sounds like we are discussing several different 'noises', so my acceptance of the issue may not apply in your case...you may have something actually 'broken'

someone mentioned it gets worse when the road is wet, good observation, the is slip more (less friction) and the tires break traction and the movement is amplfied, ie, more noticeable...rather than confined to the suspension/drivetrain as binding, noise, judder, etc., the energy is disappated moving the tire, so you feel more happening thru the steering wheel...