Mystery clonks from front suspension - let’s play remote diagnosis

dj_efk

A2OC Donor
United-Kingdom
OK folks, I’m a little stumped and in need of so guidance on this one:

Akoya’s front suspension sometimes clonks over rougher surfaces (very occasionally the rear does too although that’s much rarer so I’m ignoring that for now) - the noise clearly emanates from the drivers side front and I have to say it does seem to do it noticeable less now I have the winter wheels on with the Michelin CrossClimate 2 tyres - not sure if that’s subjective and a red herring mind given I’ve only done 50 miles since they were fitted.

I have jacked the car on both sides and rocked the wheels (also trying to identify any wheel bearing play as there is some bearing noise - there is none, which is puzzling!!) also I’ve used a crow bar to test the drop links, lower ball joints and anti-roll bar mounts: All are sound, the only issue I’ve found is a torn steering rack gaitor on the passenger side (I cannot detect play in the steering by the way). I’ve also rocked the wheel in both sides with the bonnet off and watching the corresponding top mount.

The springs are not broken and the suspension was renewed by @PaulA2 during his ownership a few years back - he then did do serious annual miles mind - although not 100s of thousands of miles in total.

I’m out of ideas - What should I look at next?!
 
Top mounts partially seized, damaged springs, damaged or failing front shocks.

Engine or dog bone mounts worn. loose under tray.

Bonnet rattling in its mounts. Wiper arm tapping the screen. Exhaust mount or flexi pipe. Loose heatshield on driveshaft or under car.


Rear shocks dust cover loose, rear springs rattling in worn out seats, loose hand brake cable.

Rear seats not fully locked in position.

Have you driven the car with the bonnet off to rule that out? Also worth having someone else in the car moving about while you drive to try and pin point the location as sound travels well in these cars
 
Dog bone mount is new, the under tray is properly attached.

It’s definitely something heavy duty (suspension) on the front right. It’s not the bonnet or seats etc.
 
Well thats a couple off my list. I take it the tyres are not over inflated? Really check the front suspension components and lower wishbone. This does appear to be the prime area so check the mounts carefully - really difficult built up. Do this weight on and jacked up. Check other items on the list and tick off the list unless something is found amiss.
 
Here’s another one for you good people. No clonks whilst driving forward, make a reverse manoeuvre and apply the brakes.... front drivers side clonk. Then nothing else ?? Handling is fine. It sounds lower than foot level.
 
So I've been having a similar problem for a while, i was sure it was a drop link, I'd inspected them and they were fine. It's only when I decided it had to be that and would change it regardless the problem became obvious - it was the anti-roll bar bush, you can only see the play when the droplink is disconnected.
 
we have recently managed to de-clonk our AUA. When purchased everything was knackered and rattling over bumps so a full suspension refresh including ARB bushes and drop links was done on a budget (but I didn't go Febi / Meyle / TRW for everything for once). Springs were replaced when the Suplexes broke early last year, but the clickety ARB-bush-like noise and occasional deeper clonk remained. Everything seemed sound when on ramps, but finally after the MOT our mechanic again commented on the noises and suggested looking at the ARB bushes / drop links again while we were replacing the dog bone. As I had Febi kits for both in the garage I agreed, and he swapped the new parts in. Even though the existing ARB bushes and drop links were apparently in good condition, replacing them with the Febis has eliminated the clicking, and the dogbone (which apparently was pretty knackered in the bush section) has eliminated the clonks. Now the loudest noise is a slightly rattly driver-side bonnet catch that I will look at when weather tidies up.. Win win.
 
Strange one this - Since I posted the above I've driven quickly over rough roads for about 7-8 miles and on normal roads for about 20 miles and I haven't heard a single clonk!!!

The only think I did when doing the above checks with the wheels in the air is move the brake fluid resevoir to one side, remove the driver's side suspension top mount nut's protective plastic cap and got my ratchet onto the nut and turned it to tighten it up (access was VERY tight, the ratchet - which is a very high quality, fine-toothed item) could only do a click each turn) - I could not detect the nut turning without turning the whole thread and top mount, but this is going by feel only plus observing what you can see from the rubber top mount from above - so who knows??

Now that I've said that, I'm certain the clonk will reappear, but as all I've done is disturbed the top mount (and possibly the shock as a result of the thread turning, perhaps this is my answer? Neither component looks worn or has undue movement I can detect mind.
 
I had similar clonk from from drivers side suspension. I renewed everything and still had clonk which was very frustrating. Now I don't mean to insult you here with the simple stuff but it turned out to be the top nut on the shock not done up tight enough. As we are aware it is quite difficult to do the nut up on the drivers side. I don't know if it all settled a bit after I had replaced everything. I'm sure I did do it up pretty tight originally. I discovered it was this by pushing up hard on the arb drop link (car on ramp on its wheels) which reliably replicated the clonk.
 
Thanks Trevor - Well I'm knocking my wooden desk top with both hands as I type this, but yes I think so!

I'm not insulted at all, just glad that tightening the top mount just a little (and I did put a bar on the ratchet to give me extra leverage) seems to have done the trick. Out of interest was there some hack you found for getting better access to the nut so I could get more of a swing on it on the ratchet? Can you detail out how you tightened yours? I'm worried that I only tightened it a little and in time the clonk may return as it needs to be even tighter.
 
I'm sure you've checked but I had this and could not trace it for a while. Turned out that the nut on the dog bone mount had come off. I was trying to trace this fault for a long time and not sure how I hadn't noticed. I guess I assumed it was suspension related.
 
I'm sure you've checked but I had this and could not trace it for a while. Turned out that the nut on the dog bone mount had come off. I was trying to trace this fault for a long time and not sure how I hadn't noticed. I guess I assumed it was suspension related.
Dog bone mount completely replaced as per my blog thread. Honestly I really was stumped!
 
Thanks Trevor - Well I'm knocking my wooden desk top with both hands as I type this, but yes I think so!

I'm not insulted at all, just glad that tightening the top mount just a little (and I did put a bar on the ratchet to give me extra leverage) seems to have done the trick. Out of interest was there some hack you found for getting better access to the nut so I could get more of a swing on it on the ratchet? Can you detail out how you tightened yours? I'm worried that I only tightened it a little and in time the clonk may return as it needs to be even tighter.
No magic solution for tightening top nut. Same as you I think, just moved as much out of the way as possible and one ratchet click at a time. Also had to hold the rod to stop it from turning at the same time.
 
Thanks Trevor - Well I'm knocking my wooden desk top with both hands as I type this, but yes I think so!

I'm not insulted at all, just glad that tightening the top mount just a little (and I did put a bar on the ratchet to give me extra leverage) seems to have done the trick. Out of interest was there some hack you found for getting better access to the nut so I could get more of a swing on it on the ratchet? Can you detail out how you tightened yours? I'm worried that I only tightened it a little and in time the clonk may return as it needs to be even tighter.
I think this might be behind the mystery clunk coming from directly behind the dashboard / windscreen edge on my everyday winter-driver project car, an occasional deep clunk when I go over road imperfections big enough to cause some suspension movement. It's not the clickety ARB noise, and it is too high / off centre to be the gearbox dogbone mount (which was new not long ago) (and unrelated to power on/power off). I had a look last week in the rain, and the rubber cap is in place on top of the strut top bolt, all of which conveniently located behind the brake-fluid reservoir so I couldn't get to it at the time but want to sooner rather than later.

Any hints on how to pop the cap off - and secondly, once the brake reservoir is out of the way, is the top nut an M12 / M14 nut - what size spanner or socket do you use?
 
I can’t recall the whether the nut was 17 or 19 but I believe the latter. The cap was very difficult to replace and it being made of soft plastic it dents fairly easily, which is annoying as you then can’t get the dent out without removing it.

Perseverance pays off in the end on all aspects of this job.
 
I can’t recall the whether the nut was 17 or 19 but I believe the latter. The cap was very difficult to replace and it being made of soft plastic it dents fairly easily, which is annoying as you then can’t get the dent out without removing it.

Perseverance pays off in the end on all aspects of this job.
Perseverence ran out in parallel with daylight this afternoon and about as quickly ... I ran out of sockets when it got to 21mm (a spark plug socket) and it was still slightly too small. I've now read at least one source suggesting that on the B4 it is a 22mm-sized nyloc on the M12 or larger thread of the shock - which corresponds to a Lambda socket which is something else I've needed - in this case an offset one with a 1/2" socket on it I can get my pry bar into, so that is ordered - also much lower profile than a socket with the ratchet head on top. There is either an Allen or Torx socket on the top of the shock shaft to hold the shaft in place while you turn the nut. Confirmed this on my spare B4s as well (which I only remembered some time after taking various pieces of the car off and repeatedly dropping the locking pliers into the undertray below the alternator!). Getting around the brake fluid reservoir though ... what fun. Removed the MAF (the reason for the locking pliers). Undid the 10mm screws holding reservoir to the bracket. Shuffled it sideways a bit. Undid both MAF and brake fluid sensor connectors and moved them out of the way. Now able to see the plastic cover to the shock, but unable to get left hand through the gap to get to it as the best angle is obscured by the Webasto! Brake reservoir bracket is only secured by one 10mm of three (on the vertical arm behind the reservoir), but this appears to be corroded in situ.. . At least the shock top cover on the passenger side was removable - with a bit of rotation and a decent grip it was possible to pop it off and back on again without issue, so I know what I'm aiming to do when I get access.. or give up and take it to my mechanic around the corner at a slightly lower cost than the swear box!
 
Oh dear, apologies Robin, now you mention it I may have used a spark plug socket on the top nut! I only mentioned 19mm being the biggest it could be as I don’t remember straying outside of the socket set I have which goes up to 19mm - but I do believe now you mention it that I may have used a small spark plug socket that I once bought to work on a Mk2 Fiesta!

As both my cars are ATL engined I don’t have webasto heaters!
 
The front suspension on my 2004 ATL has made all sorts of “plinks” and “clunks” for years. Almost 190,000 miles and on the original front suspension (both front springs have been replaced after one cracked; the entire rear suspension has been replaced).
Each year, when it goes in for service, I ask the garage (originally Audi Doctor, Stockport; more recently WOM, Uttoxeter) to really go over the front, checking if anything need to be changed: the answer, since 2009, has always been everything is fine.
If I was a DIYer, I am sure I would have changed the entire front suspension twice. As I leave it to the experts, I just drive it

Andrew
 
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