Hi Dan, suspect you got the info from the below article?

Subaru WRX Transmission - Gear Set - Turbo Magazine

Is this noise a whining sound, or the "garra garra" sound?

(this is the noise that I'm referring to: Deceleration Noise - YouTube

If this noise is ring and pinion gear noise, how can this be caused by an upgraded clutch? I have the same RPM1911N (Clutch Industries RPM) that MY99GT has.

When the noise results it's when the clutch is engaged (pedal not pressed).

My car has the standard flywheel. My car had the gearbox rebuilt (new bearings throughout and a new crown wheel and pinion) about 12 months ago. The above clutch was installed at this time, when the noise started.

How can the upgraded clutch technically contribute to the noise in this case?

Cheers
Chicane

Ohh, sorry mate, I didn't see the vid (Gay comp didn't load it).

I have not heard that sort of noise from a GearBox and as you pointed out the chatter explanation I offered is most likely a different kettle of fish.

Have you gone to see Stechnic, MMS or ASG? They would have to have SOME idea I would hope. My experiance comes from DIY installs and long nights putting my mate's cars together, and even if someone on this forum has a hunch it would be best to contact the PROS to get 100% of the story

Daniel

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MY01 JDM EVO VII - 230KW / 430NM @ 1.6BAR

I can't comment on that particular clutch but I know that the EXEDY and XTREME clutches can cause the chatter and sometimes a more emphasised noise from the transmission.

My chatter is also experianced when the clutch is engaged and decelertating.

The flywheel may be stock, however the clutch may be lighter then the factory unit (and when its getting up in the RPM range a little weight difference can make a whole lot of difference)

***EDIT when I get onto my computer I will watch the video and figure if they are the same sounds as mine.

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MY01 JDM EVO VII - 230KW / 430NM @ 1.6BAR

I know it's going back a while, but what was the solution?

springs in the clutch plate, whole thread on it here:
Wrx Clutch Exedy Rattle **solved P18** - Rexnet Subaru Forums - Page 18

Hey Strubaru, I don't have an Exedy clutch.. plus i've found the noise is greatly reduced (almost completely gone) when increasing the tyre pressures in the front compared to the back - 35 front 33 rear.

(the recommended PSI is 33 front 32 rear - on 17" wheels - so Subaru are recommending greater tyre pressure up front).

To me that suggest it is not the clutch, however there is oodles of information on the net blaming the exedy clutch. The CI RPM clutch I have has dual springs.

Correct me if im wrong here, but how could the clutch plate be to blame here? the noise is definitely not some little springs wobbling around.. and isn't the clutch disc in contact with the flywheel?

Cheers
Chicane

sorry, my reply was to redmy01owen

Thanks Strubaru. That all makes sense for my situation.

Hi RedMY01Owen,

Out of curiosity, what tyre PSI are you running?

The recommended PSI from Subaru is 33 Front, 32 Rear (well it is for my MY04 WRX with 17's).

Are you able to see if the sound changes/disappears when maintaining say +2 at the front, or try say +4 up front? (32 rear, 37 front)?

I found this solution works with my CI RPM Clutch (also single spring like your Exedy).

I am still looking for a logical explanation as to why +2 (or +4) PSI will cause a rattling clutch plate (or springs) to disappear..

I usually run 38 front and 36 rear. I can't see how tyre pressures would change the clutch noise, maybe it's not your clutch making the noise in your case.