Knocking Noise on full lock

[tajgill]

Hi,

I hope someone can help me. I'm getting a knocking noise coming from the front drivers side wheel when I reverse out of my driveway and turn the steering wheel on full lock.

I've had the wheel off and can't see anything obvious.

I'm thinking it might be a suspension bush, does anyone have any ideas ??

Thanks.

[exo]

A repeated knocking noise, whilst moving on full lock, may indicate worn CV joint.

[tajgill]

The CV boot hasn't split, could it still be worn even if it hasn't split ?

I thought it would knock only if the boot grease leaked out.

Could it be anything else ?

Thanks.

[exo]

A CV joint should last in excess of 100,000 miles. Over time. the grease breaks down and wear increases. Changing the grease every 40,000 miles may allow the joint to last indefinitely.
A lot will depend on the known history of the car. Driving the vehicle with a split CV boot for weeks or months will hasten wear considerably.

It is difficult to diagnose noise faults without actually being able to hear it.
If it is more of a graunching noise, then it may be the control arm lower swivel joint. This will normally be picked on on the MOT test.

[spartacus 68]

More than likely one or both of the upper control arms and/or the tie-rod end.

[tajgill]

Should I check for play in the control arms then ? I take it if there is no play then it's most likely a new CV joint ?

I've never done a CV joint before, how hard is it ? Looking at the haynes it says you need to remove the driveshaft which sounds a bit daunting.

How much would a garage charge for a CV joint ?

Thanks.

[exo]

You do not want to replace components unless you are certain it is defective.
If in doubt, then use the services of an independent VW/Audi garage and get a second opinion on the cause.

Replacing the control arms or CV joint is not technically difficult but it can become a frustrating / nightmare of a job if certain parts do not free up easily. The driveshaft does not have to be removed but to release the CV joint, you have to release the upper control arm pinch bolt to allow the hub carrier to move outwards and release the driveshaft and then gain access to the outer CV joint. That pinchbolt is notorious for being difficult to remove and may take an hour or more to knock out with a suitable drift and big hammer. Garage may do it quicker with access to air tools. A new bolt will be required.

For tools, you will require the 14mm hex bit to remove the axle bolt and a new bolt is recommended. The bolt is tight so have a long socket bar handy.
You will probably require a puller to release the CV joint from the driveshaft.

Not sure how much a garage will charge as rates vary. Expect 2 hours labour.

[AlecHayter]

Hi,

I hope someone can help me. I'm getting a knocking noise coming from the front drivers side wheel when I reverse out of my driveway and turn the steering wheel on full lock.

I've had the wheel off and can't see anything obvious.

I'm thinking it might be a suspension bush, does anyone have any ideas ??

Thanks.

I appreciate that this post is years old, but I have the same problem with my 2015 A5 Coupe. This happens not all the time but on cold mornings in the very same circumstances you describe. This is therefore, IMO, not a CV joint problem, nor should it be given the young age of the vehicle and the low mileage. My supplying garage sent their service manager along to my house after nothing could be replicated on their premises when the car was warmed up getting there, and the noise was heard, but he said that the noise, akin to driving over rumble strips, was normal for this and some other Audi models, including the A7 Quattro. The cause he said was the alignment of OS and NS wheels changing relative to each other in this type of manoeuvre, and assured me that the noise was caused therefore by tyre slippage on the road surface. At least he confirmed that there was no driving safety issue.

With that extra information, can anyone add anything, such as whether the symptoms have been explained in the same way? More importantly does anyone know if there is any solution.

[fourringsrus]

Maybe your 2015 A5 is a quattro? and he was referring to quattro shunt which usually shows up when tyre tread or wear is getting low

[AlecHayter]

[QUOTE=fourringsrus;1002848]Maybe your 2015 A5 is a quattro? and he was referring to quattro shunt which usually shows up when tyre tread or wear is getting low[/QUOTE
Hi, and I now learn that the knocking noise is caused by a lateral movement of the wheels (and of the tyres in particular) when on turning on to full lock. It can happen on either lock and both going forwards or in reverse. The noise is only there on first movement of the vehicle in cold conditions. I am assured that there is nothing dangerous about it, and that the A7 Quattro is susceptible as well.

Information given by a main dealer's service manager, and was backed up by an independent tyre dealer when I took the vehicle to them for a wheel alignment check. I was, by doing this, trying to eliminate all possible causes. The alignment was found to be spot on.

My A5 is a 2 litre diesel S Line Coupe (i.e. not a quattro).

It is annoying that because of the way in which the steering and relevant alignment of wheels are set up this noise is produced. I would have thought that Audi might have been able to do something about it for their vehicles which as we all know are sold at premium price.