Drivetrain rubbing/grinding noise...solved?
 

I've had this f*cking annoying sound in my drivetrain lately, came about a few months after a new clutch was installed. Confusion as to whether its a HD organic sports or OEM replacement, invoice contradicts itself. Happens only under the following conditions:
* in gear, 0% throttle & cruising along...like slowing for a set of lights before engaging clutch.
* only when car is warm...assuming means the gearbox oil is warm too.
* loudest at 2-3000rpm.

Best way to describe the noise is with this video...when you listen to it you will understand why I am fed up with this noise & want it fixed!!!!!!11ntyOMGBBQRIBS

[YT]zVQwpK68Foo[/YT]

And another video... (~1:25>1:40 is the noise)

[YT]f5Wo9DMlVRQ[/YT]

According to this thread - [url]http://forums.nasioc.com/forums/showthread.php?t=1097682[/url] - the noise is as a result of lightened flywheel with a relatively new clutch, something about there not being enough weight to stop something spinning or whatever.

My questions:
1. Does an 01-02GT come stock with a lightened flywheel?
2. Would a lightened flywheel be causing a slight squeal/shudder when driving around parking lots & a harsh on/off throttle response when crawling along at low speeds/rpm?
3. Can I get a heavier flywheel relatively easy & what are the drawbacks v. lightened? Slight loss of power?

It sounds like gear chatter.

1. But the Foz GT doesnt come with a light weight flywheel as standard.
2. No to the squeal. Yes to the harsher on/off throttle at low rpm
3. No loss of power/torque when going to a heavier flywheel. Only slight loss of throttle response.

Yeah there's plenty of name for it floating around, 'grubba grubba' is the most entertaining.

I can only assume that when the clutch was done the workshop installed a pre-machined lightened flywheel as opposed to the heavier one thats meant to go on. Explains the harsh on/off throttle around carparks & touchiness thats only been happening since it was done.

Will give the workshop a call Monday. Cheers!

LOL @ grubba grubba.. that perfectly explains the lightened flywheel decel noise.

Where/whats a good replacement if the workshop doesn't come to the party? OEM?

the flywheel has no moving parts, so its not making the noise.

more likley to be bearings in the gearbox.

doesn't really sound like a clutch type noise, like Tuna said it sounds like bearings, need to get it on a hoist and simulate the conditions to pinpoint it.

Nah I'm 99.999% sure it's right, none of the bearing noises match & I've already looked down that path with no success.

I'd be checking the diffs, even though it sounds like the gearbox, the rear diff reverberates the sound

my boss at work calls it garra garra noise.
ill speak to him tommorow and find out what he normally does to fix it

+1 on a drivetrain noise. I have a LW flywheel in my RX and the only noise I get is in say 4th gear at low speeds trying to accelerate. Does it happen in any gear in particular? I've heard about getting chattering noise in 2nd from a chip tooth. If you can get someone to run it on a hoist and check it with a stethoscope to pin point the noise...

Exedy OEM replacement clutch? They aren't the same as the Subaru OEM ones, known to make weird noises.

[url]http://www.rexnet.com.au/forum/index.php?showtopic=78962&st=180[/url]

Dunno if it's the same issue - But I avoided Exedy 'OEM' replacements for some noises they make.

^ Yeah I wouldn't know for sure until I pull the gearbox off, people are having the same issues with different clutch companies so I'm not convinced it's soley the Exedy problem. Even if it is the clutch springs a heavier flywheel should reduce the noise to a bearable level. I asked for an OEM Exedy because the new tune would lead to slipping but on the invoice it says 'Exedy Sports Tuff Organic'...except on the Exedy website there's Sports Tuff HD & a Sports Organic...No Sports Tuff Organic...

If it turns out the flywheel I've got is a heavier one (doubt it because of the other issues) then I'll just get a replacement clutch.

Will be dropping all driveline fluids when we pull the gearbox too so will rule all those out + check bearings etc. Not convinced at all that it's any of these but at least I'll start fresh.

My my99 WRX is making this exact same noise and only ever noticed it since having my new clutch installed (Jim Berry). Been trying to diagonose what it is and havent found anything yet. Ive replaced gearbox and diff fluids, no change. Even pulled the clutch back out to see it was a bad spigott or throw out bearing or clutch damaged in anyway and still couldnt find any faults. Was also trying to find a rattle at the same time but couldnt find the problem. Next step would be strip the gearbox etc down and check all bearings and teeth.

My last exedy clutch did that.
Once i replaced it with the next exedy clutch the noise went away.
I have a lightweight flywheel, clutch was a sports tuff clutch.
The only difference i can see between the two is that the first clutch had dual springs in the friction plate and the second only has single springs.

Yeah I'm fairly certain thats whats going on here, if the flywheel in there at the moment is light I'll get a heavier one & see how it goes...or half tempted to pony up for a new one & do the swap myself.

Sorry to res this thread from Feb, but i had a new HD clutch installed last month and am experiencing very similar issues as you apg. The mechanics at work took it for a drive today and confirm the issue was present in 1st through 4th on 0 throttle. They suggested it seems to be some form of vibration in the box/flywheel, but they are going to check with the company that replaced my synchro to see if they replaced or machined the flywheel when they installed the clutch.

Did you ever get a result from this apg? if so what was the fix?

The clutch i got was the "RPM kit: RPM1911N" from [URL="http://ciperformance.com.au/product_catalogue/"]http://ciperformance.com.au/product_catalogue/ [/URL]

[QUOTE=MY99GT;546302]
The clutch i got was the "RPM kit: RPM1911N" from [url=http://ciperformance.com.au/product_catalogue/]High Performance clutch systems, CI Performance, performance clutch, LS1 clutch[/url][/QUOTE]


Hi MY99GT,

I have exactly the same problem that you have mentioned and the replacement clutch is of the same model too. What was your findings/outcome?

Cheers
Chicane

My clutch has also started to make this noise since being replaced with an Exedy stage 1 racing clutch (organic plate) by Evolution R. I had the stock STI flywheel machined and re-used. What were the outcomes for everyone else?

I also get a chatter when I decelerate in my car the clutch/flywheel, its a common problem with the WRX with a HD clutch/flywheel due to the lower rotating mass.

Not harmful in anyway if this is the problem:
[COLOR=#000000][B]"This is a common problem, but technically not a problem at all. It's just a matter of inconsistent factory backlash in the ring-and-pinion gear. Some models do it more than others.[/B]


[B]You can fix the problem, but not with performance in mind. You can replace the factory flywheel with a heavier model to keep the gearbox loaded, thus eliminating a decelerating noise.[/B]


[B]Going the opposite direction with the flywheel weight will usually get rid of the noise, however the lighter flywheel will be noticeable in how quickly the car finds its powerband. Suggestion: Get over the noise. It's not a big deal, and certainly not worth compromising power."[/B]
[/COLOR]

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

[url=http://www.turbomagazine.com/features/0305tur_subaru_wrx_gear_set/index.html]Subaru WRX Transmission - Gear Set - Turbo Magazine[/url]

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

(this is the noise that I'm referring to: [url=http://www.youtube.com/watch?v=f5Wo9DMlVRQ]Deceleration Noise - YouTube[/url]

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

[QUOTE=chicane;666793](this is the noise that I'm referring to: [URL="http://www.youtube.com/watch?v=f5Wo9DMlVRQ"]Deceleration Noise - YouTube[/URL]
[/QUOTE]

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

[QUOTE=chicane;666793]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.
[/QUOTE]

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.

[QUOTE=MY00GC8;529812]my boss at work calls it garra garra noise.
ill speak to him tommorow and find out what he normally does to fix it[/QUOTE]

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

springs in the clutch plate, whole thread on it here:
[url=http://www.rexnet.com.au/forum/index.php?/topic/78962-wrx-clutch-exedy-rattle-solved-p18/page__st__170]Wrx Clutch Exedy Rattle **solved P18** - Rexnet Subaru Forums - Page 18[/url]

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.

i suspect by doing the different tyre pressures would lightly load up the centre diff by creating ever so slightly different rolling diameters, saying that your noise could be a centre diff bearing

Wtf... Tyre pressures changing clutch noise?

That's a first...

EDIT: Actually, I am sure it's the clutch plate vibrating around after all..

Would I recommend a Clutch Industries (CI) RPM Clutch to anyone? I don't care if its heavy duty or not, but if it rattles around - it's crap!

Cheers
Chicane