Technical Panda multijet 75hp 2009 Rear shocks. Internal re-bound spring rattle?

[keefO]

Could this be it? Any thoughts or experience of the differences, issues with oil shocks or gas ? twin tube? do some have internal return springs?
09 plate multijet, 115 k miles:
knocky knock coming from the rear, both sides, low speed .Developed over last 12 months.
Up on lift , crowbar and shaker plate and checked :
engine mounts - exhaust brackets - rear subframe bushes - rear springs - rear bearings - brake shoes - fuel tank - door locks - rear door gas struts - rear light light clusters.
all ok. Nothing obvious. !!!

Heres the thing, rear shocks, replaced two years ago.?
Last try, I removed both rear shocks drove carefully around the houses…no knocky knocks ‽ huh.

 

[jackwhoo]

No internal return springs as the vehicle spring is strong enough.

 

[The Panda Nut]

Gas filled can leak all the gas without external symptom. What brand did you use. I am suspicious that cheap ones might have a very short life. 2 years is a bit thin though. I havn't heard dampers knocking before apart from failed bushes when they really rattle. Suspension noises are notoriously difficult to track down back to front let alone left to right. The inside workings of dampers are something I dont give a great deal of thought to, fitting the recommended type has always been my preferred course. Generally the higher spec seem to be gas filled. How you are supposed to tell whats best without back to back tests in an identical car with new parts I do not know. I did change the standard dampers on my 100HP for Bilstein B4 and they were excellent apart from the bottom eye being the wrong size and rattling. If the car is not bouncing then the dampers will still be working and maybe you have another issue. Try removing the dampers and the springs, then you can check them, and also check the swinging arms are not the cause, at the same time. In the run of things worth the effort I suspect. ISometimes its something daft and unexpected that causes these noises.

I last fitted Monro dampers which are the OEM supplier for the Panda and they are very good and reasonably priced.

 

[keefO]

hi..thanks for the ideas… not sure what the replacement shocks are? no logos!. Not a good sign eh hem. The light, knocky knock is equal both sides and at rear. No bouncy bouncy from shocks, must be operating ok.
No internal return springs as the vehicle spring is strong enough…hmm ok, i have had both springs out and checked length, barely a mm less than spec.

I am hearing that they should have their final torque down at ‘WoW’ ...weight on wheels ? i will do that tomorrow. Not convinced how that would make much difference. but open mind.
… 'Sometimes its something daft and unexpected that causes these noises’…yep. even removed spare, and all tools…boot open to check door latch. etc. seat belt spools…its endless.
thanks , watch this space.
BTW, the last mystery rattle i had in a FIAT was, from new,! a 1986 Uno Turbo i.e.. Three years later we cut a hole in a rear cavity and found a unused bolt rolling around. ffffs

 

[koalar]

Are the bolts a tight fit in the shock eye

Post some photos of the shocks

What length are they fully closed and extended

There rest position should be fully extended

 

[keefO]

tight fit in shock eye? thats another possiblty. thetho’ number of times i had them on/off recently never checked that. i could see how that would affect the lower fit, however the upper has the bolt head hard against the inner surface of the shock eye.
maybe its a bad fit on the lower, here you have the flange on the spring mount and the trailing arm that could be too wide and not coming together with a 70nm torque. ? although at one time i did check that by just fitting the shock at the lower point , torque up and found it impossible to move…by hand?
if that makes sense!

 

[keefO]

Gas filled can leak all the gas without external symptom. What brand did you use. I am suspicious that cheap ones might have a very short life. 2 years is a bit thin though. I havn't heard dampers knocking before apart from failed bushes when they really rattle. Suspension noises are notoriously difficult to track down back to front let alone left to right. The inside workings of dampers are something I dont give a great deal of thought to, fitting the recommended type has always been my preferred course. Generally the higher spec seem to be gas filled. How you are supposed to tell whats best without back to back tests in an identical car with new parts I do not know. I did change the standard dampers on my 100HP for Bilstein B4 and they were excellent apart from the bottom eye being the wrong size and rattling. If the car is not bouncing then the dampers will still be working and maybe you have another issue. Try removing the dampers and the springs, then you can check them, and also check the swinging arms are not the cause, at the same time. In the run of things worth the effort I suspect. ISometimes its something daft and unexpected that causes these noises.

I last fitted Monro dampers which are the OEM supplier for the Panda and they are very good and reasonably priced.

hmm that bottom eye fit is sounding suspicious…i wonder, it's certainly a tight fight in the space between spring lower mount and the trailing arm hole and torqued down to 70nm , without the top mount fitted, it wont move. i might deliberately loosen off and see if things get worse?
btw have had the springs off, they ring like a bell and are within a mm of the spec length.
ta for the ideas.

 

[The Panda Nut]

tight fit in shock eye? thats another possiblty. thetho’ number of times i had them on/off recently never checked that. i could see how that would affect the lower fit, however the upper has the bolt head hard against the inner surface of the shock eye.
maybe its a bad fit on the lower, here you have the flange on the spring mount and the trailing arm that could be too wide and not coming together with a 70nm torque. ? although at one time i did check that by just fitting the shock at the lower point , torque up and found it impossible to move…by hand?
if that makes sense!

On my Bilsteins the eye was too big and the bolt too small. I tired a raft of things to rectify thos and gave up and bought Monro which were instantly fine. I asked a facor about thicker bolts with the same thread and they said it couldnt be done.. Short of making some I couldnt stop the rattle. A case of near enoiugh in not good enough.

 

[keefO]

On my Bilsteins the eye was too big and the bolt too small. I tired a raft of things to rectify thos and gave up and bought Monro which were instantly fine. I asked a facor about thicker bolts with the same thread and they said it couldnt be done.. Short of making some I couldnt stop the rattle. A case of near enoiugh in not good enough.d

On my Bilsteins the eye was too big and the bolt too small. I tired a raft of things to rectify thos and gave up and bought Monro which were instantly fine. I asked a facor about thicker bolts with the same thread and they said it couldnt be done.. Short of making some I couldnt stop the rattle. A case of near enoiugh in not good enough.

dammit had that very thought going thru my head last night, dreamt of shims and the like!!! how to make up any tolerance deficits, turn sloppy into an interference fit?

 

[DaveMcT]

Ive had a really hard to find clunk that happened on (some) small traffic islands. It sort of sounded like the rear end but I eventually homed into the nearside front. Strut stripped (all ok) new top bearing replaced problem still there. The it failed MoT with the bottom ball joint pin loose in the clamp. I spent and hour trying to replicate it but once I had a suitable lever and angle it was obvious. The M8 clamp bolt was retaining the ball joint pin but it was not getting clamped. I (brass) shimmed the clamp, the clunk has gone and passed MOT. I will probably replace the hub as it has to affect tracking.

Yours might be fine but some noises are hard to locate.

 

[keefO]

Ive had a really hard to find clunk that happened on (some) small traffic islands. It sort of sounded like the rear end but I eventually homed into the nearside front. Strut stripped (all ok) new top bearing replaced problem still there. The it failed MoT with the bottom ball joint pin loose in the clamp. I spent and hour trying to replicate it but once I had a suitable lever and angle it was obvious. The M8 clamp bolt was retaining the ball joint pin but it was not getting clamped. I (brass) shimmed the clamp, the clunk has gone and passed MOT. I will probably replace the hub as it has to affect tracking.

Yours might be fine but some noises are hard to locate.

thank you …one more mystery 'clunkity klunk' to add to the memory bank!! Maybe the forum should build a list of these for all vehicles?