lofi Posted September 29, 2020 Author Report Share Posted September 29, 2020 I forwarded the clip to Center Gravity, who I use to do all my suspension work, and they concur with a view that it is a ball joint, either on the tuning forks or the lower arms. I'll do the forks myself and cross my fingers, else up to CG for them to do the lower arms and geo. Link to comment Share on other sites More sharing options...
nixster Posted September 29, 2020 Report Share Posted September 29, 2020 Good luck with the work. I think as well as parts binning Porsche are also production engineering to reduce manufacturing cost rather than improve performance. I noticed that the diagonal brace on the rear suspension of the 987 is a hollow aluminum extrusion but the part that does the same job on a 981 is a simple top hat section. No prizes for guessing which is cheaper to make and less robust. Link to comment Share on other sites More sharing options...
temporarychicken Posted October 8, 2020 Report Share Posted October 8, 2020 Having only had the car for 7 years and 32k miles..... I'm getting a very similar rattle/clatter from the front. It's intermittent and normally only over rough surfaces. It has similar characteristics in that it appears to be coming from behind the dashboard. However, knocking suspension joints have a habit of making themselves acoustically apparent in the cabin in deceptive ways. Because the rattle/clatter appears to be coming from the right-hand (driver's) side I have already changed the off-side lower front track-control coffin arm. This made no difference. The rattle/clatter was also apparent both before and after an X75 conversion that I undertook fairly recently. This conversion replaced: struts x4 Anti-roll-bars x2 Front drop-links x2 Front tuning forks x2 To summarise, the only suspension part that I haven't replaced on the front is the near-side (left-hand) lower track-control coffin arm. And yet this rattle/clatter persists. It doesn't affect driveability but it annoys me in ways that even marriage cannot. I've bought some chassis ears (basically a set of four metal clamps and some headphones). I'll go out later and make some recordings. The 981 is getting to the age where wear-and tear stuff will start to happen. This thread is very interesting and show's were at that point now. Link to comment Share on other sites More sharing options...
lofi Posted October 8, 2020 Author Report Share Posted October 8, 2020 Be very interested in where you get to. Currently getting hold of tuning forks for a half decent price is difficult so I have not tackled them. However, I am pretty sure it is suspension as it is quieter in the wet (although it could also be the new front tyres being slightly under inflated, though I doubt it). I am therefore pretty sure it is suspension. Link to comment Share on other sites More sharing options...
temporarychicken Posted October 8, 2020 Report Share Posted October 8, 2020 I got genuine TRW tuning forks from Autodoc.co.uk for 46 quid each a while back - part JTC1618. They had the porsche part number ground off so they were basically discount oem stock. Not sure if they still have them there at this price though............. Link to comment Share on other sites More sharing options...
lofi Posted October 9, 2020 Author Report Share Posted October 9, 2020 They’re out of stock unfortunately Link to comment Share on other sites More sharing options...
temporarychicken Posted October 9, 2020 Report Share Posted October 9, 2020 Sorry to hear that. I've got a couple of known good ones here that I replaced unnecessarily when I did the X75 conversion. If that helps you, PM me. They're a doddle to fit as I'm sure you know already. Link to comment Share on other sites More sharing options...
lofi Posted October 9, 2020 Author Report Share Posted October 9, 2020 37 minutes ago, temporarychicken said: Sorry to hear that. I've got a couple of known good ones here that I replaced unnecessarily when I did the X75 conversion. If that helps you, PM me. They're a doddle to fit as I'm sure you know already. Apparently you cannot receive messages for reasons I do t understand Link to comment Share on other sites More sharing options...
daz05 Posted October 9, 2020 Report Share Posted October 9, 2020 Top mount ok? Link to comment Share on other sites More sharing options...
lofi Posted October 9, 2020 Author Report Share Posted October 9, 2020 1 hour ago, daz05 said: Top mount ok? It looks ok in terms of delimitation but it could be gone. If the forks don’t do it then it will be into center gravity to do whatever is needed Link to comment Share on other sites More sharing options...
daz05 Posted October 10, 2020 Report Share Posted October 10, 2020 9 hours ago, lofi said: It looks ok in terms of delimitation but it could be gone. If the forks don’t do it then it will be into center gravity to do whatever is needed I mention it because I knew of a Cayman with a strange rattle and it ended up being the top mount. Link to comment Share on other sites More sharing options...
lofi Posted October 10, 2020 Author Report Share Posted October 10, 2020 Had the car on a lift today. No obvious movement in suspension parts. Very similar sound can be produced when steering the front wheels by hand and reaching the end of the steering travel, ie against the steering stops. Link to comment Share on other sites More sharing options...
temporarychicken Posted October 10, 2020 Report Share Posted October 10, 2020 Deleted some old messages so PM working now I hope... It's interesting that nothing showed up on the lift. Mine is the same situation. The steering is the obvious next place to look..... Link to comment Share on other sites More sharing options...
lofi Posted October 11, 2020 Author Report Share Posted October 11, 2020 Thanks to temporarychicken I will be trying some new forks and I have also ordered a pair of drop links. If those do not do the trick then I will go to CG and they can mess around with the lower arms and the inner and outer track rods. Link to comment Share on other sites More sharing options...
Ninesomething Posted October 12, 2020 Report Share Posted October 12, 2020 I read a thread somewhere in which a guy had replaced everything - top mounts, shocks, coffins, tuning forks - and found out it was a track rod end. Usual thing in that the noise was worse when the car had been driven hard which makes the grease hot and thin and if it's any kind of sealed joint then components can rattle. When I had them check my front suspension the only place they could find any play - and it was a tiny amount - was one inner track rod. In my case I still think it's tuning forks. We'll see. Link to comment Share on other sites More sharing options...
lofi Posted October 17, 2020 Author Report Share Posted October 17, 2020 So, fitted known ok tuning fork arms today and the sound is the same. So that is one item off the list. I have drop links on the way so will give that a go. If it's not then I will book in for Center Gravity to diagnose and fix Pic for those who are unsure of what a tuning fork is. Its actually properly called a track control arm but it looks like a tuning fork. They also 'ring' like a tuning fork. Link to comment Share on other sites More sharing options...
lofi Posted October 28, 2020 Author Report Share Posted October 28, 2020 Further update. Swapped out the drop links for new ones. No change. So now looking like lower control arms or the top mounts. Booked into center gravity on the 4th December Link to comment Share on other sites More sharing options...
temporarychicken Posted October 30, 2020 Report Share Posted October 30, 2020 Good luck with CG, look forward to the next update. Link to comment Share on other sites More sharing options...
lofi Posted December 6, 2020 Author Report Share Posted December 6, 2020 Ok. Been to CG and they think they’ve found the issue. It is not possible to correctly torque the front tuning fork bolt. This means the the metal centre of the bush isn’t clamped properly and is moving. In fact when I got there the bolt was able to be undone without a bar. With the bolt removed there was swarf in the chassis fixing. The fix is to re thread the chassis and that means removing the front sub frame. Didn’t have the right Timesert so I’m back in January to have it done. Also, the rear coffin arm bal joint has gone so that needs doing as well. so I have my fingers crossed that is the issue and the rattle goes away. It has actually got worse. The bolt is glued in with super lock tight at the moment, the stuff that needs heat to unlock. Link to comment Share on other sites More sharing options...
daz05 Posted December 6, 2020 Report Share Posted December 6, 2020 1 hour ago, lofi said: Ok. Been to CG and they think they’ve found the issue. It is not possible to correctly torque the front tuning fork bolt. This means the the metal centre of the bush isn’t clamped properly and is moving. In fact when I got there the bolt was able to be undone without a bar. With the bolt removed there was swarf in the chassis fixing. The fix is to re thread the chassis and that means removing the front sub frame. Didn’t have the right Timesert so I’m back in January to have it done. Also, the rear coffin arm bal joint has gone so that needs doing as well. so I have my fingers crossed that is the issue and the rattle goes away. It has actually got worse. The bolt is glued in with super lock tight at the moment, the stuff that needs heat to unlock. Do you think that has happened when you removed and refitted before Lofi? Cross threaded? Link to comment Share on other sites More sharing options...
lofi Posted December 7, 2020 Author Report Share Posted December 7, 2020 9 hours ago, daz05 said: Do you think that has happened when you removed and refitted before Lofi? Cross threaded? It’s not impossible. Means the sound will still be there when sorted. Either way it needs fixing. Link to comment Share on other sites More sharing options...
lofi Posted December 15, 2020 Author Report Share Posted December 15, 2020 Next update will be 15th January once the work is complete. I presume the rear coffin arms are the same as the 997? Link to comment Share on other sites More sharing options...
temporarychicken Posted December 16, 2020 Report Share Posted December 16, 2020 Good luck with next January! From experience it could be possible to cheese the thread on the body where the front subframe and tuning fork meets it accidentally, although any hardened steel bolt wound into tapped aluminium is a potential cheese risk. The all aluminium suspension of the Boxster is a selling point, but it does have this particular downside. Either way, a timesert will sort it. Hopefully some labour can be saved through 'dangling' the front subframe andundoing the front-most bolts completely, whilst leaving the rear-most bolts undone just a few turns. This will possibly allow access to timesert the damaged thread in the chassis. I did exactly this, albeit for a different reason in order to create access when I fitted the X73 anti-roll bar. Link to comment Share on other sites More sharing options...
lofi Posted December 17, 2020 Author Report Share Posted December 17, 2020 Thanks tempchick, I will pass on that advice as anything to reduce time will be good Link to comment Share on other sites More sharing options...
lofi Posted March 30, 2021 Author Report Share Posted March 30, 2021 So, after many delays due to travel restrictions the car has spent a week at Center Gravity and Chris has followed his process. The car is now back, rattle free, full set of Michelin fitted, and the geometry set up all properly. The subframe did not need a timesert in the end but one of the bolts was stretched (by 1.5mm!) so all the subframe bolts were replaced. Phew - I can get back to enjoying the car. Link to comment Share on other sites More sharing options...
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