I just replaced the flywheel, clutch disc and pressure plate on my 02 Accord, and now I have a slight vibration that varies throughout the RPM range.

I have poly front and rear motor mounts, so I'm used to some vibration. Compared from going stock mounts to poly mounts, I'd say it vibrates about 60% more than before I replaced the flywheel and clutch components. Not quite to the extent of pulling the balance shaft belt off. It barely begins to show around 2krpm when the steering wheel vibrates as if I'm going down the highway with unbalanced tires, but goes away around 2500rpm. Then it comes back around 4000, and vibrates steadily up to redline. It really feels like it hits harmonic points as the rpms go up, if you know what I mean.

I used reputable parts and torqued everything down in a star pattern to factory specs. The flywheel weighed exactly 8lbs less than stock. Do light weight flywheels generally not dampen the engine vibrations as well? Or maybe the 1-piece design has something to do with it?




Modified by paradigm_shift at 4:11 PM 10/9/2008

 

i dont think its your flywheel ... im running ACT Clutch Kit and XACT ProLite Flywheel on my '01 accord ... no problems here ...

 

It HAS to be something with the clutch, pressure plate or flywheel, because it didn't vibrate like this before. There are no rattles or symptoms of anything being loose, just the vibration. I'd hate to think something was out of balance.

 

I would have to agree that it's most likely a Flywheel / Pressure Plate balance issue. Just for the reference to the 'harmonic" observation. The thing is; you've several things which actually made a mostly tolerable issue absolutely maddening.
1) Urthane engine mounts - Transmits vibrations to the chassis
2) Lightweight Flywheel - Doesn't damper the engine firing pulses as well as a heavier flywheel.

Worst; it's an absolute Bit**h trying to address this (as well you know from the installation bul***t)

Were these a matched set, or did you mix / match? You can either make the commitment and try to rephase* the Pressure plate to the flywheel, or go for a packaged assembly (if you can find one).

This is one of those times that hindsight really ******s you off. If available, I would have had the balance checked b4 I installed the %^$#* things

P

* Rephased: Incrimentally turning the Pressure Plate until you line up the heaviest part of the pressure plate to the lightest point of the Flywheel. It involves a LOT of trial and error.

 

not trying to resurrect from the dead, but i have this scenario as well. recently (last week) finished my auto-to-manual swap and the swap involved a lightweight fidanza 8lb flywheel with an exedy clutch. i made sure the mounts were torqued per the shop manual order, and i have that sliiiiiiiiiight car vibration from ~2-2500rpm. i don't notice the vibes at 4k rpm though.

just another person's experience with it....

 

HEY p_adams your back! haha. To the OP, I am going with the motor mounts as your problem. I have a 9 lb flywheel with a six puck stage 2 on stock motor mounts and no problems at all.

 

Generally (all things considered), lightened flywheels will cause additional engine vibrations at idle &/or low RPM's. There is less mass to dampen the impulses from the power strokes. Harmonic (rpm sensitive) vibrations are usually out-of-balance related.
It gets really weird when you add Polyurethane Motor Mount inserts, and gets downright miserable if a mount were to collapse.
Most domestic motorheads learned long ago to balance the entire assembly b4 installation, particularly if an aftermarket flywheel was involved.
The severity of the vibration will determine your course of action.

P

 

I agree p_adams, the factory designs the oem flywheel to control the harmonic vibrations. But from what i have read and from my mixed matched clutch/flywheel setup, I think that the "vibrations" from flywheel upgrade doesnt affect all motors.

 

All motors differently? Yes. The more cylinders, the better (more power impulses per revolution)

Some applications can see improvement by rotating the pressure plate with relations to the flywheel. This can be done easily with transmissions with inspection covers, but can be a real %^$#@ if the tranny has to come out. Sometimes you can luck out and align the heavy spot on the pressure plate with the light spot on the flywheel.

This mirrors the theory of aligning the sidewall dot on your brand new Yokohama and the wheels valve stem

 

I'm with P on this one lightened flywheel = less mass to help smooth out the engine firing pulses......combine that with stiffer mounts and you get a lot more vibration