My Golf has a knocking noise from the front N/S when the front N/S wheel goes over drain covers, small bumps etc.

It has 1 month old Koni STR T suspension (uprated dampers and -35mm springs) and I've tried the following:

New top mounts and bearings.

New anti-roll bar mount bushes.

The clearnance between the anti-roll bar and driveshafts is around 60mm. These definately have not hit each other, even the dirt on both components is unmarked.

I removed both anti-roll bar drop links, made sure the anti-roll bar was not able to knock and tested it, but the knocking was still the same, so it is not anti-roll bar related.

New lower ball joint.

New track rod complete with track rod end.

New Audi TT rear bushes for the front wishbones. (Front bushes are showing no signs of damage.

Checked every bolt related to suspension and steering is tight - all are fine.

Removed dog bone mount and checked this is ok (I fitted powerflex bushes last year).

Checked tighteness of the N/S gearbox mount bolts which are accessible with the airbox removed.

All CV joint gaitors are good, and the the backlash in the drivshafts is normal.

I cannot feel any play in the wheel bearing.

The exhaust is clear of all bodywork etc, and all mounts are in good condition including the centre one which I've seen broken on a few of these now.

All bodywork in this area appeas as new - I cannot find any broken spot welds or other damage.

The next thing I will try is swapping the front struts left to right to see if the knocking is strut related.  The O/S is perfectly silent, even when driving over rough ground.

So, what have I missed?  I have spent a lot of time (and money) trying to locate the cause of this, but I cannot find a thing wrong.

 Any chance it is the coils of the spring knocking together?.

 I have heard of this happening with other manufacturers lowered springs. The solution was to put some rubber/plastic tubing over the "dead" coils ie the ones that were resting on each other. 

I realise it is only affecting one side of the car, but there could be a slight difference in the two front coils that is just enough to do something like this.

dubster67, that is something I can look in to.  Hopefully when I swap the struts from left to right this will show up any issues with the springs if they are slightly different.

Is the damper unit a cartridge in the strut with a threaded collar holding it in place, if it is then the collar may have come loose allowing the cartridge to move in the strut which will cause the knocking.

Neil

 old_n07, as fare as I am aware it has a crimped cap, this covered by a plastic trim.  But I will remove the trim and take a look.

 I know that that cap has come loose on a strut I had in the past (screw in type)

You are getting to the point I was at with a noisey rear N\S I had changed bushes etc and the shocks were new so in the end I paid for a diagnostic at PSI and it was the new shocker that was causing the noise which has since been changed under warranty. So it may be worth getting a diagnostic done then at least you will know where to start.

Neil

 Interesting that the damper itself was knocking.  I've had the screw cap loose before too.  I'll see if I can pop the the plastic trim off and have a look at the cap tonight.

Decided to rebuild the N/S strut last night, and could find nothing wrong.

The damper works exactly as it should, the spring isn't hitting anything.

I'm out of ideas now.

 Did you fit new drop links Phil

 Finally someone witht the same problem, but unfortuante not to have an answer......

I am getting the same noise as you but can't find it for the life of me i have checked everything (well i guess not everything!) but i can't find anything loose but still the knocking noise persist over any bumps in the road......... If anyone has any ideas it would be a great help or if you figure out the answer, if you could let me know, as i would love to get rid of it!

Also my car is going in for a service on the 29th so if they find the problem i shall let you know what it was!

Cheers

Mike

 No, they look fine, and to cornfirm that the anti roll bar is not the problem, I removed both drop links and made sure the anti roll bar could not move (it was clamped tightly by the arb mount bushes), then drove the car.  With the anti roll bar disconected and both drop links on the garage floor it was still the same.

 I get a bell like rattling noise from passanger side. I traced it to be a damged thread on the sliding part of the brake caliper which had been damaged due to overtightening the 9mm bolt at some time when changing the brake pads.I still get this as I can not source a new hub.hope this helps. 

 6580gareth, Thats something I hadn't considered, however I'VE SORTED IT

It turned out to be the top mount bearing. I had fitted brand new VW bearings a few months ago, and one seemed a bit rattly. Last week I swapped it for one of the originals from my car, but there was no difference.  At the weekend I fitted another, originaly from my my dads S reg Mk4, and now it is nice and quiet. There was 1mm of horizontal movement on both the bearing and the original from my car.

 ive had a similar problem, i have changed the top mounts but may be worth looking at them again

 sorry im not following how can a bearing sort your knocking noise? i have the same knocking noise and its so horrible sounding.

I pickeded it up from the garage today hoping it would be cured after paying for 2 new wishbones etc etc, frove out of the garage and * clunk* i slow down and *clunk* a lot of swearing later...

i have fk highline stainles steel coilovers, i have changed the top mounts and no differnce, drop links i have had off n look fine too...

read arb is the answer but can someone point me inthe right direction..

My golf is low 50mm + if i get a new arb n bushes will this stop the stress on the new wishbones n bushes i have just had fitted? also the noise is just when i go over some bumps but more of a clunk when i stop n pull away.... any help would be appreciated its driving me mad!!

 The bearing had some sideways play which allowed the strut to slightly move sideways at the top.  The knock occured as the bearing stopped the movement.

Mine is still nice and quiet.

 I have a similar problem - fitted coilovers on saturday just gone & driving up to ed 38 was a nightmare - crash, bang, knock! All from the N/S front.At first I thought it was the anti roll bar knocking on the driveshafts, but I've just raised the car today & it seemed quiet at first, but after around 10 miles it was knocking again.

Andy.

 andy_vw, the front dampers are likely to be inserts within the strut body. They need to be clamped tightly by the large nut that holds them in. The nut is at the top of the strut.  The piston rod passes through it.  If the nut is loose the damper will move up and down over bumps causing a knocking.  Also check that the front stut is tightly clamped into the hub, and not sliding up and down - this will also cause knocking. 

 Ahhh i see worth alook i suppose i put new top mounts in but not new  bearings... can u buy them seperatly?, is it worth getting some standard arb bushs fitted just to see if it cures it or is it more cost effective to go straight in for poly bushes and arb it? and if i get a uprated arb (not sure which one tho) will this sort out all the wishbone angles? the garage said the angles are wrong cos its low? whats the c ost of getting arb bushes fitted at to and new arb and polys

 The bearings are available seperatelt, and are pretty cheap.

Std ARB bushes are also very cheap, only about £2 or £3 per side, so it's probably worth changing them anyway.

An uprated ARB will have no effect on the wishbone angles, to change them either raise the ride height, or look into Audi TT hubs with a taller lower section which positions the lower ball joint closer to the road, therefore altering the wishbone angle.

How low is your car?  I've never had problems with handling caused by wishbone angles.

Going in next thursday, new arb front n back and polys, bearings, new dog bone mount(just while they are there may as well have it done)... hopefully fingers crossed this will cure it, oh yeah not taking it to VW :) i have ordered the parts and a local garage is fitting them.

I will let everyone know how i get on thanks for the help

 New top mounts seemed to solve my problem. (£9 ea from steelers) Although I did have everything apart, so could've been something else...

 New eibach's fitted and dog bone mount and omg what a differnce, knocking is none exsistant although now i have swapped both wish bones, topmounts, ARB. amazing! no knocking!