Knocking upto 10mph

**randall977** · 05-05-2009,10:20 AM

Ok, I've never experienced it.

**Adam A41.8T** · 19-05-2009,12:59 PM

Hi,

Did you find out what the problem was? I think this sounds like the same thing I have got with my rear wheels on my 2003 '52' A4 1.8T Quattro Sport. The symptoms sound exactly the same.

Thanks,
Adam

**randall977** · 19-05-2009,03:24 PM

Well tbh I was a bit wrong on the symptoms. It actually does it when pulling off while turning as well and upto around 50mph but only under certain accelerations??? I can only think that it's a CV joint - which I guess could do the same on the rear with a quattro. I bought two complete drive shafts off eBay a few weeks ago for £130 the pair (genuine new VAG). My plan is that when it really starts to annoy me I'll swap the drive shafts over...

**chris.r.** · 04-05-2010,01:11 PM

Have you checked the shock mounting rubbers?

I had this the other day on a Golf, and was pretty surprised about the find, they were worn! We replaced the shocks anyway (after 180tkm) and it's gone..wasn't the CV joint at all...

**ciaran** · 06-05-2010,10:26 AM

Is it possible that it may be the snub mount ?

**spartacus 68** · 08-05-2010,10:36 AM

The A4 suspension has lots of problem areas. I personally wouldn't look at the CV joints, unless one of the rubber dust sleeves was torn and the joint had become contaminated.

Turn your attention to the upper control arms, the tie-rod end, ARB bush, front wheel bearing. Jack up the car and hold the wheel at a 10-to-2 position and rock from side to side. There should be no play what-so-ever.

**P4ulyt** · 23-11-2010,02:34 PM

i've had the same problem too. limited to 1st (where its worst) and 2nd gear. as torque reduces it goes away. very annoying. My CV boots are ok too. I thought it might be the drive shafts too. what do you think? is the CV joint part of the drive shafts or are they together as part of the same job? I wouldn't be doing this myself, i'd take it to a mechanic.

**spartacus 68** · 23-11-2010,10:30 PM

Originally Posted by P4ulyt

i've had the same problem too. limited to 1st (where its worst) and 2nd gear. as torque reduces it goes away. very annoying. My CV boots are ok too. I thought it might be the drive shafts too. what do you think? is the CV joint part of the drive shafts or are they together as part of the same job? I wouldn't be doing this myself, i'd take it to a mechanic.

Take it to the mechanic. Suspension isn't for the faint-hearted. I've spent many a winter's day trying to free seized bolts when my fingers were frozen. The tie-rod end is a straight forward job. To identify, jack up the wheel and hold at ten-to-two position. Using lateral movement, rock from side-to-side. Pay close attention to the tie-rod end. If the ball-joint is worn it will be easily recognisable as it 'clicks' and you should see movement. Its essential to measure the distance the threaded lock-nut and tie-rod end. A tracking check is worth the money to save you wearing out tyres prematurely. Some people fit a cut bicycle inner tube filled with grease and tied of with cables ties over the thread and lock nut on the tie-rod end for easy maintenance.

The upper control arms are a little more difficult, as you've the spring compression and strut to contend with. Again, hold the wheel at the ten-to-two position and look at the pinch bolt on the strut. Any movement here and the ball-joints are worn. Tell-tale signs are split rubbers, etc. Pinch bolt needs to come out to replace, and it's usually an oxy-acetelene torch to generate sufficient heat to release. If it were me, I'd do both arms. The spring needs to be compressed and it's a strut-out job to replace.

The CV joints themselves are normally okay. However if the rubber dust sleeve has torn or worn, then the CV grease will more than likely be on the inner wheel arch. Pay close attention to the rubber and replace before it fails. A new CV joint is £80 minimum. Suitable repair kits are available from GKN Driveline including a new hub bolt, grease, alloy ties, the CV boot itself, and other sundries.

The ARB bush can also wear. Look at the rubber inserts. If torn, or badly worn, then it will be straight forward to replace. A scissor jack is useful for this job. Other culprits could be wishbone bushes, etc.

Lastly - check the condition of the spring. Not unusual for the spring ends to break - especially at this time of year given the state of our roads. Obvious signs will be a slight drop in height, sharp edges on the spring ends. The knocking sound could be because the spring is no longer seated properly. Fit a new suspension top mount when refitting.

More details here: http://www.AudiDIY.com/b5a4phps/b5a4suspension.php
http://audizine.com/forum/showthread...al-and-Install

**P4ulyt** · 25-11-2010,11:41 AM

I had a knocking from the O/S front last year. Audi said supension, mechanic replaced that and it was still there. replaced the upper arms and bushes and solved the problem. Although that has now come back its this bloody cats eye type thud i don't like. i had the track rod ends replaced too last year when they seized and its been worse since then. Its definately back into the workshop. I've never known a car be so heavy on suspension type bits.

**P4ulyt** · 06-01-2011,09:07 PM

i've now taken the car to three different mechanics. all of them agree the knocking thud like cats eyes is coming from the rear.

I have had the suspension lower arms checked and replaced, tracking checked, 2 new tyres, replaced track rod ends and its all still there.
audi specialist wants to take my drive shafts apart to try and find the problem but is also suggesting the differential as he thinks its coming from the rear and it also makes a crunching noise when on full lock and this is when the diff comes into play.

it doesn't stop me driving it and my car has only done 85k so i'll keep going for the moment. i wonder if i just leave it until it fails. anyone solved this problem yet? I'd be gutted if it was the diff as that shouldn't go yet.