fullymatted.
Back to search
911uk

Front knocking noise - coffin arm ball joints?

Add to repair workspace
Open repair workspace
Original source
11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHFront knocking noise - coffin arm ball joints?

Reported repair

Replace top mounts and anti roll bar bushes (both of

Reported resolution
1
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that report a fix
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Reported fix

After replacing top mounts and anti roll bar bushes (both of which cured knocks) I was left with what you described and it was a tuning fork replacement that cured it.

Front knocking noise - coffin arm ball joints?
Read full discussion summary

Leading evidence: 'Replace top mounts and anti roll bar bushes (both of' (1 discussions report resolution; 0 report an unsuccessful attempt). Across 1 matching discussions, The most frequently discussed action is 'Replace top mounts and anti roll bar bushes (both of' (1 discussions). For that action, 1 discussions report a resolution and 0 report an unsuccessful attempt. The most frequently reported fix is 'Replace top mounts and anti roll bar bushes (both of', supported by resolution reports in 1 discussions. These are forum reports and suggestions, not a confirmed diagnosis.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

Read captured replies

1 matching discussions · 11 captured posts examined · 0 partial discussions

Compare 3 other evidence results

Replace some time ago

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster

Pretty much all the other suspension arms were polybushed and changed some time ago.....

Front knocking noise - coffin arm ball joints?

Replace then it's not

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

if replaced then it's not that .

Front knocking noise - coffin arm ball joints?

Use lever bar

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

you would jack it up and use a lever bar to see if there is actual play in the ball joint.

Front knocking noise - coffin arm ball joints?
Frequently discussed actions (4)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Replace top mounts and anti roll bar bushes (both of

1
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that report a fix
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Reported fix

After replacing top mounts and anti roll bar bushes (both of which cured knocks) I was left with what you described and it was a tuning fork replacement that cured it.

Front knocking noise - coffin arm ball joints?

Replace some time ago

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster

Pretty much all the other suspension arms were polybushed and changed some time ago.....

Front knocking noise - coffin arm ball joints?

Replace then it's not

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

if replaced then it's not that .

Front knocking noise - coffin arm ball joints?

Use lever bar

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

you would jack it up and use a lever bar to see if there is actual play in the ball joint.

Front knocking noise - coffin arm ball joints?
Actions with reported resolution accounts (1)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Replace top mounts and anti roll bar bushes (both of

1
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that report a fix
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Reported fix

After replacing top mounts and anti roll bar bushes (both of which cured knocks) I was left with what you described and it was a tuning fork replacement that cured it.

Front knocking noise - coffin arm ball joints?
Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • 911uk: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T124918Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

If I jack the front of the car up, wrap my arms round a front wheel and pull the top of it back and forth towards me there's a slight knocking.... is this most likely play in the ball joint of the front coffin arms? or should I be thinking something else? There's an increasing knocking felt from the front at low speed. Top mounts were fairly recently changed. Same for droplinks. Pretty much all the other suspension arms were polybushed and changed some time ago..... Am I also imagining things that someone released coffin arms with serviceable/replaceable ball joints?

POST 2Original post

Could you get a mate to rock the wheel while you feel all the joints?

POST 3 / ORIGINAL POSTEROriginal post

I think I'm going to have to do this or be more thorough prying on each arm - some forum threads suggest that this type of knocking comes from wear on the inner mounting point of the "tuning fork/wishbone" track control arm - which is preferable as ultimately considerably cheaper/easier to deal with

POST 4Original post

Mine failed MoT for this last year - I hadn't noticed but once the coffin arm was off, there was definite play. It could also be top mount gone if you can make it clunk on lock to lock steering.

POST 5Original post

Wiggle the wheel top and bottom and play can be the shock .. won't cause a noise though .. Bottom coffin arm ball joint .. won't normally cause a noise but is possible .. you would jack it up and use a lever bar to see if there is actual play in the ball joint. Top strut mount .. if replaced then it's not that . When driving then it depends on the type of noise .. a sound clip would help but a common one is the diagonal arms .. on a bump you get a bonk .. then bonk bonk .... bonk bonk bonk .. Anti Roll bar bushes can give a louder but the same type of noise .. these are both pothole related .. you need a bump in the road to cause the noise .. this i think is not your case ? Look at the shock in the middle when you check this free play .. does it move ? Can you describe the noise when you drive the car please if no sound clip is possible . Play side to side is several other things .

POST 6 / ORIGINAL POSTEROriginal post

Tends to be lower speed i.e. under 30 and slightly uneven surfaces, rather than potholes.... bonk... bonk bonk..... bonk... bonk bonk bonk... Would be a pretty good description. No side to side play at all and movement and noise is very slight, but I'm becoming a bit hyper attuned to it(!) Definitely feels like is narrowed down to the 'tuning fork' arm (now that I've seen a video about the nature of that inner bush) or movement in the shock (which I'll have to have a look at as deMort suggests)

POST 7Original post

Had this on mine was play in the shock push the bump stop dirt cover up and put your finger on where the chromed shock shaft disappears into the strut. Now get someone else to rock the wheel, you'll feel the play. PM me if you need a good low miles front shock I have both early (3.4) and later 3.6 in my spares cache I'm selling off Also if it only happens when the car is warm it might be inner track rods.

POST 8 / ORIGINAL POSTEROriginal post

The cars on Ohlins, so I'm rather hoping its not the shocks

POST 9 / ORIGINAL POSTEROriginal post

Now I wonder if I'm losing my mind slightly... - the deflection I'm getting seems to be just in tyre The car still has its winters on (Pirelli sotto zero 3s - all the exact Porsche spec sizes on the right Porsche wheels) - could it be an issue with the bead/rim?! Is that possible? Planning on swapping onto the summers next weekend... maybe that's the check and maybe I bring that forward... :dont know:

POST 10Original post

I had exactly this kind of knocking, plus several others. After replacing top mounts and anti roll bar bushes (both of which cured knocks) I was left with what you described and it was a tuning fork replacement that cured it.

POST 11Original post

Your description is a diagonal arm noise .. you won't feel any play in these as they are an annoyance and not a problem . diagonal arm / tuning fork .. which ever you want to call them would seem to be the issue . I will add that if original then around 50K miles they start to knock . Best guess anyways .

This is a source reference. Confirm exact model applicability in the original material.