Ok, it seems there is a lot of discussion as to the origins of tranny noises, what they are, and how a clutch can affect these sounds. The truth is, the stock clutch (along with many other OE clutches) has many springs and dampers that are not included when swapping to a performance clutch.

Exedy's particular OE design (and similar designs to other OE companies) employs what they call a "Wide Angle Dampener" (WAD). The WAD has special characteristics and damper springs that are tuned to absorb noises that are transmitted from the motor to the gearbox and vise versa. It also absorbs and prevents other harmonic noises transmitted from the engine bay area. These tuned springs work together allow for 38 degrees of movement from the center of the disc, where a normal disc turns 8-11 degrees.

For Example: Every time the engine fires, it sends a vibration thru the crank. The harmonic balancer in the front of the engine absorbs half of this noise, and the other half of the noises travel thru the crank in to the gearbox. This has been apparent in the past decade since transversely mounted engines have greatly increased torque capacity in many applications (not only Mitsubishis, Supras and Subbies). Also the packet spacing in bell housings have been greatly reduced in the past decade, where the clutch is located, thus adding to the vibrations. The new WAD clutch is now OE in vehicles such as the Evo VIII, Subaru STI, Honda Civics and Accords, Chevy Cobalt, etc. This is a simple way of controlling the vibrations at the clutch disc (before reaching the gear box).

Another method to absorb vibrations is using a Dual Mass Flywheel (DMF). Late model Subarus have adapted this along with Supras, Hondas and the 350Z. The first flywheel of the Dual Setup has spring dampers, which try and intercept transmitted noises before they even reach the disc. However this is an expensive option and adds weight and cost to the setup. Therefore Exedy developed the patented WAD plate as a cost effective and weight saving device.

With all said, there is NOTHING wrong with your tranny, clutch or otherwise if your only symptom is clutch noise. However, there has to be an acceptable level of comfort (noise) that a user needs to sacrifice when dealing with an aftermarket clutch whose focus is performance not noise absorption. In other words, the price you pay for increased torque capacity of the clutch disc, is added noises to the gearbox – bottom line.

To further understand what I am talking about and to get a visual reference on how the dampening mechanism works, please visit http://exedyusa.com/technical/movies.shtml and watch the “Damper Specialist” video.

Please Also See Attached for WAD and DMF pics.

 

I have an Exedy twin disc (cerametallic) and have no tranny noise. The only noises I have comes from the floater plates when the clutch disengages (normal) and a groaning sound when slipping the clutch. I am pretty sure I can get rid of the groaning sound by blowing all the clutch dust out through the inspection hole though.

 

One additional factor that I should mention - and this is a textbook example...

*Every car is different* some cars may expierence certain harmonics from the A/C that transfer throughout the vechicle, others may not.

The clutch is no different. Also depending on Cams, Exhaust, etc you may experience more or less noises from the engine in general.

But, as a safety, expect a sacrifice in comfort, whenever you install a performance piece.

 

Good post. I just installed an Exedy Twin disk, and all the noises that I would associate with the clutch are present and within what i would call normal and acceptable. My question is in regard to the "Decel Noise" that most all evo's have (clutch engaged, throttle closed, above 3000 rpms). My Decel noise was noticeable before the clutch, but not to the point I would want to do anything about it. After installing the twin disk, either the noise is being amplified by the new clutch, or coincidentally my previously benign decel noise has erupted into a big problem. The noise is horrendous is 3rd and 4th gears above 3000 rpms.

Is this the clutch making the noise more apparent (loud), or do I have a new problem? The car has not been launched or even driven aggresively since I put in the new clutch.

 

I've got the Road Race Noname Clutch, and in 3rd and 4th gears the decel noise is LOUD. It's kind of annoying, but I'll live.

 

not a prob with the act.

 

No Clutch Noise.

 

Is it louder after the new clutch? That has been the only unexpected new noise with the Exedy. I'm just wondering if others have experienced an increase in that particular noise as well.

 

Oh yeah, without a doubt it is much louder after the new clutch. I thought that would go away with the new clutch, but it's about 5x louder now. lol

 

Well that's encouraging to hear, thanks.

 

Matt,

So pleased to have you join the conversation here. I imagine Daikin/Exedy is quite happy with the countless numbers of us buying your clutches for our Evo's, including myself. I had your Exedy Twin (cerametallic) put in by a local shop here in the DC area, and there are quite a few noises coming from my tranny now that are either increased or were not present before, including a drastically amplified deceleration noise (off-throttle, slowing). I suspect that my early-build Evo may have the warranty-issue bad gear syncros perhaps, but I do not otherwise know the cause of this.

My question is, how would I know whether or not a dealer actually installed my clutch correctly? I told them to replace the throw-out bearing and assume they did so but I cannot be sure...if they did not, how might I know?

I have excessive clunk-clunk-clunk "chatter" when attempting to engage clutch from a stop no matter how warmed-up the car gets, a "whirr" when I engage the clutch (expected), and also a "groaning" on deceleration that is amplified. The clutch chatter appears to be pronounced in a 1-2-3 or 3-2-1 shift after high-speed 4th and 5th-gear driving when the car is fully warmed up, as well, and the clutch does not seem to want to engage.

I have not removed my restrictor plate though I have put a steel clutch line in. I have never replaced fluid in my transfer case, though have replaced tranny fluid with Red Line (indicated in my sig).

Does is sound to you like my problems are normal, or should I visit a dealer or second performance shop for a second opinion?

Thanks in advance for your help,
Adam

 

Adam - I had the same clutch in my car (untill today actually... testing to see how the Stage 1 holds up to me )... and my "diagnosis" over the internet are your noises are normal. Although Mitsu dealers are a bit loopey at times, I have to imagine they replaced your TOB at the time - there no real way to check without pulling the clutch unfortuently.

The "whirr" and the "groan" are typical. The "clunk" may be something else gearbox related...

For the record... I had noises with my twin disc, and just put in the stage 1 for testing. Did the noises go away? Nope.

The real issue is getting rid of that disc... once you get rid of it, the gearbox noises let loose.

Do noises mean there's a problem? I don't think so, but if there's odd engagement characteristics or grinding, then there is reason for concern.

Best of luck,

 

Adam, is your decel noise loud enough that you're sure the car in the lane next to can hear it? My car had next to NO decel noise before installing the twin disk a month ago, and immediately afterward had so much I was sure something was somehow broken during the install (done by myself and a couple of local DSM/EVO guys). As unbelieveable as it probably sounds, after installing the clutch, I have not launched the car until today at our first auto-x. Like you, I'm trying to gauge what's 'normal' here, so any input you might have would be very much appreciated. Thanks.

 

Im telling you. First hand expierence (with many cars, not just mine and not just Evos) Twin disc or Stage 1/2 you're going to have that decel noise.

In addition to the Stage 1 clutch I just installed I have a FRESH Team RIP tranny put in. Are any of the noises gone? Nope.

Loud decel, and audiable idle... just the nature of the beast. If you *dont* get these noises, consider yourself one of the lucky few.

 

Yep , i got it to Loud decel nosie and loud rattle at ideal more so when the car is warmed up . Exedy twin