Thanks for checking.

I don't *think* the behavior I'm seeing is unexpected with a digressive curve setup on the struts. I could be wrong.

When I was over at Goldcrest we bounced one of the safari cars to compare it to mine and it behaved the same way (but with no squeak). I can't swear to it but I think they use the same/similar setup.

Sounds like the bushing might be turning on the race. Pull the polybronze out and apply the polyurethene glue (forgot actual recomeneded product but it's in the instructions) and glue the bushings into the metal chassis bosses. Ensure that the bearing is not binding on the shaft due to improper spring plate alignment. Remember you need a bit of lateral play in the spring plate after the tb cover is torqued down. If the spring plate doesn't drop (without the tb installed) and the cover plate is torqued, then you need to add washers (spacers between the chassis boss and the spring plate cover)

I\an idiots guide to finding squeaks :

Do this one item at a time and listen for a difference ..

Anything that can be removed , remove it .
For example , swaybar links will totally eliminate any movement and is allways my first stop ( modern porsche links seem to last 1 week , or 10 miles . Whichever comes first .)

Second step is spray cleaner liberally over moving joints one at a time , and again listen for a change .


Third step is grease the 5h1t out of the joints one at a time .
Wd40 can be used as an easy quick solution , but Vaseline etc as worked well in the past for me , as it lubricates and also adds a layer of sound insular\toon when piled on .
Once you’ve found it , your either replacing of cleaning and greasing anyway so don’t worry about pet jell too much .
Silicone spray is also good , but your Bodyshop will hate you :D

Fourth step is turn the stereo up

..and bounce that rear-end while having an assistant look at the shock tops within the engine bay, and then the shock bottoms, and then the sway bar end links, and then the sway bar mounting brackets.

If you've altered by installing struts in the rear in place of shock absorbers, maybe there is missing rubber pads between the coiled springs and their retention plates and you are hearing the coiled springs slapping their retention plates ?

In your video, the noise sounds like a suspension clunk. When you quickjack it and that jack is safety-locked up, just grab and push pull or hang off things to see if they move. Sometimes I've used my 3' prybar and force-checked the various rubber suspension bushings on syaw/stabilizer bars and their end-links, shocks/dampers/struts and their mounts, trailing arm and torsion bar mounts, and ball joints on my American muscle cars and trucks

To clarify, it sounds like you’re thinking the bushing on the chassis side of the tube is moving. If that’s true then I could watch the zirc while a helper bounces the rear to see if it’s moving, right?

I had asked Chuck about this a while back and his first thought was that I need to add spacers. I was hoping that someone would confirm the sound so I’d have an idea if I’m on the right path.

I have been doing step 4 for a while. :D

I used the silicone because I thought petroleum-based lubricants on rubber was a no-no.

Removing the swaybar is easy and makes sense from a process of elimination.

I recorded the video on my iPhone. Sounds like that tend to not be recorded very faithfully. There is a big difference in playing it back on my iPhone and my laptop. It definitely sounds more like a clunk on my phone and much more of a squeak/groan in person. The first time I played it on my phone I thought it sounded a lot more like a clunk so that’s why I made that disclaimer.

I’ve got to go out of town on business for a couple of days. Working on seeing if I can line up a friend or two to come over Friday or Saturday to see if we can find the source.

I was thinking it is most likely something to do with the PB bearings. Next would be the Bilsteins.

Strut/shock... the originals were sent to ER to be refurbished and re-valved. If it was installation problem then it was operator error on my part.

Appreciate all the helpful tips. Just need to get some time in the garage to sort it out.

Did a little more searching... this lone post sure seems like it fits the bill.

https://forums.pelicanparts.com/porsche-911-technical-forum/860798-elephant-spring-plate-bushing-suggestion.html

Lined up some help on Saturday morning. Best part is my business trip to South America was posted until next month so I should have plenty of time to work on it this weekend.

Thinking out loud...

IF I have to add shims to the spring plate cover, is it possible to do so without having to completely disassemble everything? If I put a jack under the trailing arm to take the load off the bottom bolt that the spring plate hits, shouldn't I be able to loosen the cover bolts and then remove one at a time to add the necessary shims?

Trying to think of a way to do this without having to redo the rear alignment.

Emailed Chuck @ ER. If it turns out that it is the lateral play with the spring plate cover, he agrees that I should be able to add spacers one at a time without having to completely disassemble everything.

Will report back.

Here's an update.

It seems like I have an alignment problem with the left/driver side torsion tube poly bronze bearing. Where the inner zirc used to be at 9 o'clock, it has now rotated itself to an 11 o'clock position and is jammed up against the top left cover bolt.

My buddy Robert came over this morning and we started troubleshooting. I have a stethoscope and the sound seemed to be coming from the spring plate.

We started with the right/passenger side. I loosened the spring plate cover bolts and then pulled each one at a time and added some washer shims. That seemed to eliminate the squeak from that side. It was never really bad on that side, but it definitely helped.

Feeling encouraged that this was going to be a simple fix (it never is), we went over to the driver side. No amount of loosening the cover plate eliminated the squeak or changed the sound in any way.. I thought maybe it just needed some grease and that's when I noticed the inner bearing had rotated.

(Note: I have the Dual Keuhl A/C condensers and the forward-mounted condenser attaches to the top right spring plate cover bolt on the right/driver side. That makes working in that area much tighter.)

It seems that no amount of adjusting the spring plate cover on the left/driver side changes the squeak. I'm thinking that the bearing is either rotating in the torsion tube or it has become mis-aligned.

I didn't want to have to completely disassemble the left/driver side but I'm thinking that's what I'm going to have to do. I hate that job. Not looking forward to it.

I also disconnected the sway bar just to rule out that possibility. No change.

Took a lunch break. I'll take a look at it again this afternoon.

One last thing. It definitely sounds like something is binding at the beginning of the suspension compression and then releases. 2jmotorspots was definitely spot on with that assessment.

Did more troubleshooting yesterday and this morning.

Not sure what to do next.

- Sway bar removed.
- Shocks disconnected from trailing arms.
- PB bearings greased
- Both torsion plate covers removed. Started completely over with shims. 1.5mm lateral play verified with feeler gauge.

With the car up on the QJ and the shocks disconnected. I can bounce the trailing arm up and down. No squeak.

Put the car on the ground, squeak is back.

I have had helpers bounce the car but I cannot seem to isolate the sound with a stethoscope. It sounds the same no matter where I place it.

I’m not sure what else it could be.

Ideas on what to try next?

Have you checked the banana arm pivot by the trans?

Perhaps remove the outer spring plate bushing and replace it temporarily with a rubber bush?

I was in the middle of putting everything back together when you replied.

It is the trailing arm bushings. Soaked them in silicone spray and the sound is 99% eliminated.

I have a set of ER monoball bushings on the shelf. I hesitated to do that job before because I was concerned it would make the ride too harsh. Guess that job is in my future...