Clunk noise from front off-side

[zcacogp]

Chaps,

In advance of some football tournament thing coming up, I'm having problems with my off-side. [&:] However, the off-side in question is not at all footy related ... it's the front off-side of the S2.

In the last couple of days it has started making a slightly disconcerting 'clunk' noise. It's more than a tapping, but not too heavy; it doesn't sound like a broken wishbone, for instance. It almost sounds like a coil-bound spring. It's not consistent in terms of when it produces the noise, but it seems to be on light loading and unloading of the side, so generally during gentle cornering. However, the handling doesn't seem to have changed in any significant way - it still 'feels' the same on the road as before. It doesn't make the noise often; the car has done about 100 miles in the last couple of days and I have heard it four or five times.

I haven't had a chance to get it all up in the air and have a look yet. I should be able to do that at the weekend. Does anyone have any suggestions of what I should be looking at or for? Coil-bound spring is one thing, broken ARB mounts is another; anything else that could fail which would bring about these symptoms?


Oli.

 

[chrisg]

Obviously, I'm no expert and it's difficult to diagnose by e-mail....

My best guess would be a lose bolt somewhere in the ARB linkage or where the ARB mount (2 x 13mm) into the chassis rail. I would also check that the drop link that connects the ARB to the wish bone hasn't sheared off. These are a hollow barrel with a shank welded to them that goes through the 2 x large washers and 2 x rubber bushes.

Other things to check, are all the bolts that hold the track control arm onto the car tight ? = 2x at the back with the castor mount 17mm and the long 19mm bolt that holds it into the engine cross member.

If you're unable to see anything really obvious straight away, with the wheel off and the car well supported off the ground use a crow bar to mimic the suspension moving up and down.

Other bits to check, if none of the above:

4 x 13mm nuts that hold the strut into the inner wing mounting point.

1 x 22mm nut (you'll need a large spanner and small one to hold the shocker inner shaft ) that locks the shocker into the top mount.

2 x 19mm (I think) nut/bolt combination that hold the shock onto the hub and are adjustable for the camber

bolt/ nut combo that holds the front hub onto the track control arm = pinch bolt

Daft one I know, but are both the caliper bolts and the two small torx head bolts that hold the disc onto the hub tight ?

If you've exhausted all of these and all is OK, then you're running out of options.....[]

 

[zcacogp]

Chris,

I'd dispute your opening statement; being able to come up with a list like that, sitting at a desk (as opposed to looking at the thing in front of you) would most certainly mark you out as being an expert of some magnitude!

I'm pretty familiar with the workings of what goes on under there, but that's a very helpful list of things to check. Thank you. One assumption I am making is that it is a problem with the front, but given that noises can travel around cars in amazing ways it could be at the rear. But the back is possibly simpler (no steering mechanism, although there is a drive mechanism) so it shouldn't be too difficult.

The front ARB mount on one side broke about a year ago - the U-shaped bracket that clamps the ARB down, and I replaced it, and the other side as a precaution. I think my next suspect is, as you said, the mount for the end of the ARB, where it attaches to the wishbone.

I'll keep you posted. Thanks again for your input.


Oli.

 

[vince944red]

Stuck brake caliper can produce some odd noises as well A rythmic thumping. If you are accumulating a lot of brake dust on the wings very quickly - then thats a good sign somethings up.
But ARB sounds a good one

 

[Mike_Pollock]

As the others ARB favourite.
One addition to the list of possibles, broken spring.
I hsd one go (on a passat years ago) and a friend had one more recently, investigation with a supplier showed getting to be quite connom
Mike

 

[chrisg]

Thanks for the acknowledgement ! I am sitting at my desk but could have been in the garage on the wifi

I would place odds on it being ARB mounting to the track control arm that's rusted through... I remember refreshing the suspensions on my S2 years ago and being shocked as to the how rusty the barrel/shank joint was

 

[zcacogp]

Chris,

Yes. ARB end mount is top suspect. Although I have noticed no change in the handling; when the centre mount went, the change in handling was immediately noticable - the car pitched quite alarmingly on any left hand corner (and was worse the longer and more sweeping the corner was.)

Vince, jammed calipers, thanks. Another one to look for (and probably quite easy to spot too - great!)

Mike, Hmmm. Broken spring is something that has sneaked into the back of my mind. I fear that may be a possibility as well. Which would be a prize pain. It's quite common, particularly on older cars. I changed the suspension on a friends' scirocco last year and that had four broken springs. And another friend had two broken front springs on his 928 when he took it apart. Speed bumps and potholes are strongly to blame I understand.

Hmm. Socket set to be dusted off on Saturday morning, methinks.


Oli.

 

[DivineE]

I would guess the bush that sits in the front ARB right under the power steering pump leaks has been corroded over time and slipped out leaving the bar sitting in the metal support loop with no bush. It wont move far so wont have any major effect on the cars handling bit will clunk around under light cornering as you describe.

 

[zcacogp]

That's so simple to check I could almost do it in the client car park before I go home - thanks!


Oli.

 

[chrisg]

Dammnnnnn I've been top trumped on the front-clunk diagnosis front !

I hate to admit it, but this is a prime suspect that I never thought of..... Bugggger....

Good shout DivineE.

On both my 944's this insert has/went soft due to the PS leak, should have thought about it...

 

[zcacogp]

Insert is a poly item - I uprated them about 3 years ago.

Should be fairly PS fluid-proof. (Still worth checking tho!)


Oli.

 

[zcacogp]

ORIGINAL: chrisg
I would place odds on it being ARB mounting to the track control arm that's rusted through... I remember refreshing the suspensions on my S2 years ago and being shocked as to the how rusty the barrel/shank joint was

And the prize goes to the man sitting at his desk when he could be in the garage on WiFi! 'Tis indeed the ARB end mounting. Sheared straight through at the point where the barrel joins the shank. Rust, I guess. And age.

Will be calling my local OPC tomorrow and asking whether they have a 951 343 075 00 in stock, and if not how soon they can get one ...

Thanks again ChrisG.


Oli.

 

[DivineE]

Chris you spoke too soon! Good call[]

 

[Super_Marv]

ORIGINAL: zcacogp
And the prize goes to the man sitting at his desk when he could be in the garage on WiFi! 'Tis indeed the ARB end mounting. Sheared straight through at the point where the barrel joins the shank. Rust, I guess. And age.

Will be calling my local OPC tomorrow and asking whether they have a 951 343 075 00 in stock, and if not how soon they can get one ...

Thanks again ChrisG.


Oli.

I had one of these 'go' recently on my 968. Handling slowly started to deteriorate but I couldn't put my finger on it, as there was no creaking or groaning sounds. Finally, when I went to take my car in for its service, it started making a creaking sound and I asked my indie to check it out for me. The droplink had broken where the weld joins the circular section of the droplink. Handles soo much better now that it has been fixed.

I ordered a spare one - not sure if my OPC had them in stock as I ordered a few bits and pieces with it too. Anyway, I collected my order a few days later - the droplink is surprisingly expensive at £23.52 + VAT each (Then minus 10% PCGB discount)

I removed my front ARB last week to fit new washers to the outer droplinks, as they were the incorrect type, for some reason. I'd say if you're replacing the droplink it's worth fitting new washers, as they're only £1.34 each and the lock nut is at the top only a couple of quid too. May even be worth replacing the bushes, if they're fairly old, as new ones aren't that expensive.

As I've repeated elsewhere, while my front ARB was off, I removed the other ARB bushes and applied some red rubber grease to the inner shafts of the bush. Made them rotate far, far easier and my front end is now much smoother as a result.

Finally, while you've got the droplink off, inspect the hole in alloy arm where the cylindrical bushes push into. One of mine was suffering from quite a bit of alloy corrosion, which was preventing the cylindrical bush from seating correctly. I scraped out any corrosion with a flat head screwdriver, sprayed on some rust remover, left it to dissolve for about 15 minutes then, cleaned it all up and when re-assembling put red rubber grease between the alloy arm and the cylindrical bushes.

I wonder if it's worth painting the droplinks with something like Epoxy Mastic or Bilt Hamber Hydrate 80, to stop them from rusting and failing?

 

[Northern924]

If you buy the lock nut for the drop link from your OPC they are only 15p each exc. VAT []

Drop link rubber mountings are only £1.34 each exc. VAT as well from your OPC, I bough all bushes/washers etc for the front ARB for £27.21 inc. VAT just a month ago.

And as I'm having a similar problem I just had a quick look under mine and hey presto someone has sheared one of the ARB hanger chassis bolts on the N/S, tap and die over the weekend to accomodate a new bolt by the look of it []

 

[zcacogp]

Parts purchased. Part (x2 - one for each side) and rubber bits (x4 - two for each side).

Came to over £50 from an OPC! A LOT for not much metal.

Nuts are boggo M10 nylock. 52p for 10 from toolstation. And bought some penny washers as well, although they are a little smaller than the metal washers in the assembly so can't be substituted.

Just about to fit them all ... I seem to remember that it is a bit of a fight to get it all together as you need to flex the ARB a little.


Oli.

 

[Northern924]

Is it the full droplinks that you have replaced? Just done mine as well.

But in the end on mine it was a cracked bracket that holds the ARB to strap from the chassis, and I mean completely split!! No wonder it was drifting from side to side, need to source a repalcement, just done the bushes as well must have already been a fracture in the metal already and the extra rigidity of the bush must have finished it off.

I'll take a pic tomorrow when I get the chance

 

[zcacogp]

Yes, both droplinks. And yes, one was completely destroyed - the tube was cracked and disconnected from the rod.

Thinking about it, I can only blame potholes and speed bumps. Both will cause one wheel to articulate heavily independently of the other and put huge stress on the ARB and mountings. And we have enough of both of those evils 'round here ... thanks for nothing to the people who 'maintain' our roads.

I re-greased all the ARB mountings on the front ARB at the same time, and it's MUCH smoother to drive now. I don't know what made the difference - the new droplink or the greasing of the mount points, but it's a great improvement. Steering is smoother and it moves more easily on the road. And no more annoying "clunk" noise. I haven't driven it hard enough to tell whether the handling is improved, but I can't see how it wouldn't be ...

All the best with yours Paul.


Oli.

 

[Northern924]

Cheers Oli, just had to edit my post realised I didn't word it right LOL

One of my droplinks had been welded by a PO which is why I replaced mine, the price I mentioned didn't include droplinks which is why i asked.

Forgot to mention that the ARB brackets had been welded as well!! For sake of what in the long run isn't a massive amount look like the PO or his indie were welder happy[&:]

Brackets are only $11 from Pelican so can't be that much from OPC

 

[Super_Marv]

Glad to hear your car feels much improved now, Oli!

Greasing the ARB bushes definitely makes a difference - I greased my ARB bushes after the droplink was replaced and it definitely made a separate improvement.

I greased the two bushes on the rear ARB over the weekend, which was really easy. When I took the rollbar off, the bushes were not moving freely. Again after applying red rubber grease, the bush rotated around the ARB far, far easier.

It's a job I recommend anyone to do - those ARB's need to rotate freely around the bush, the suspension isn't working as effectively as it should, if there's no grease and friction prevents the ARB from rotating.

As for the inner two bushes on the front ARB - the clip which holds in the bush is £5.40+VAT, each and the droplink is £4.74+VAT, each. So not that expensive and certainly not worth welding!