Bought a used Evo 4 days ago, wanting to see if this is Transfer case related or just the flywheel.. maybe even an exhaust rattle. Rattle noises coming once I decelerate, goes away when I get back on gas. Doesn't make noise when in neutral or idle. From previous owner, he says it may be the flex plate due to the clutch.
03 Evo 8 with ACT Street Series Clutch, maybe OEM resurfaced flywheel.


Video of what I am hearing. Noise is 0:18. Normal for ACT?

Video seems to be listed as private. You'll need to change it to "unlisted" in your youtube studio settings before we can see it. This way only people with a link can view it.

Changed to unlisted, my bad.

Changed to unlisted, my bad

I have a tool called "chassis ear' that may help you. They aren't that expensive. Basically it is a little box that lets you put little microphones all over the car, and you can listen to each of them by switching a switch.

There are many threads about this similar sounding problem. Most commonly from a heavier clutch and pressure plate paired with a lightened flywheel. Nobody truly knows what these sounds are because they require a transmission specialist or removal of drive train parts, which nobody wants to do and rightfully so.

It's either a bad TOB, lightened flywheel chatter, clutch teeth weight noise, etc. Something along those lines.

I had an upgraded Exedy pressure plate and organic disc installed with a resurfaced ACT streetlite flywheel and this noise developed not so long after I had both installed by a normal transmission shop, not a Mitsu speed shop. The sound is annoying AF and is always on deceleration and goes away under even the slightest load. It's never gotten worse but perhaps louder. Never caused mechanical failure as well.

This problem sucks but only proper diagnosis from a trans specialist would help.

post #40 is your answer

https://www.evolutionm.net/forums/ev...e-decel-3.html

My 9 does the same thing ACT and lightweight flywheel here also. Parts were installed by previous owner I thought the noise was coming from worn driveshaft carrier bushings. Odd that it would be the lightweight flywheel but it's that same rattle on decel. I guess when it comes time for me to change my clutch out I'll swap the OEM flywheel back in.

Thanks for clearing this up.

Let's trade cars for a short drive sometime soon. Mine makes the same noise with a lightend flywheel. Curious to see if ours sound the same. We are running the same clutch too. Maybe the same flywheel too?

Well I found the issue lol.. driveshafft bearings went bad and chattered.. now I just want to see, from what it looks like in the picture the parts I need to fix this issue. Here is what I have found on STMTuned. Would you guys go STM or OEM.

-Driveshaft Carrier Bearing Support Bushings (8-Piece Set of 4 Bushings)
https://stmtuned.com/collections/mit...pport-bushings
-DriveShaft Center Support Bushings
https://stmtuned.com/collections/mit...pport-bushings
-Driveshaft Boot Repair Kit
https://stmtuned.com/collections/mit...oot-repair-kit
-Driveshaft Center Bearing Insulator
https://stmtuned.com/collections/mit...ring-insulator

LOL WTF never seen that before. Good luck.

I would get he OEM bushings. Since the driveshaft bearing bushings themselves are very compliant and flexible, the solid mount bushings don't really do too much to hold the driveshaft in place. This is the experience I had with solid type bushings, not worth the added cabin noise.