Odd jangly rattly noise coming from transmission

[andygo]

I had my Cayman 981 jacked up at the back today to ceramic coat my recently refurbed wheels.

As I was undoing the drivers side rear wheel it rotated and made an unusual noise. It certainly wasn't the normal clunk that you get as the gears or diff use up any backlash, but almost a tinny rattle, lways repeateble as I rotated the wheel slightly.

The nearside wheel when rotated to and fro just makes the normal clunk that that you would expect. Can't see anything externally loose, noise seems to be coming from the gearbox.

Any suggestions?

Car drives as normal, although I did hear similar noise a couple of weeks ago traversing a speed hump.

[Youforreal.]

Have you checked the 6 bolts on the driveshaft, unlikely but worth a check!

Possibly a YouTube vid of the sound would help someone give you an idea/area to look at.

[ChrisW.]

ON a 996GT3 that I owned I sometimes heard a strange "boing/click" which I was told was a rotating spring ??

Edited by ChrisW. on Saturday 1st March 19:02

[andygo]

I’m going to jack it up again tomorrow and get my wife to rock the wheel whilst I get a closer look/listen. I’ll record the sound and report back- realise it’s hard to pinpoint a noise remotely.

It’s my 4th porker and never noticed this phenomenon before.

[kev b]

Stone trapped behind the backing plate?

[ChrisW.]

Yes that's a kind of singing noise ... generally they come out when you reverse the rotation of the wheel ...

[Schuey_911]

kev b said:

Stone trapped behind the backing plate?

Most likely this and as said above reverse the car a decent distance and it should help. Sometimes forward and reverse a couple of time and it sorts itself out.

[andygo]

Hmmm, had trapped stones before rattling against the disc and backplate- this noise is more from the gearbox location, rather than outboard.

I can have a better peep tomorrow with my lovely assistant!

[kev b]

Maybe a heat shield or exhaust clamp then?