Lighter Fly-Wheel Vibration

[Animal15]

4AG-T50,

After nearly a year finally got the car tuned, idle is OK…

Here is my problem I got new clutch kit with lighten weight fly–wheel (3.7kg) when it’s idling there’s a vibration (when compare with OEM Clutch kit it's really bad) and rattling sound inside the car; but when I put the clutch down it goes away…
(Crank is Balance with Clutch kit and pulleys, changed Oil, new bearings etc..)

Is this common with lighter flywheel? Will it go away after few KMs?

[Hurricane]

sounds like your flywheel bolts might be loose dude! or the pressure plate.
had a mate do the same think, didnt torque his bolts up and they came loose.
i can't think or see how a lighter flywheel can/would induce any vibration if balance correctly.

maybe somthing in the box? id be double checking the flywheel bolts though.

dan.

[oldeskewltoy]

4AG-T50,

After nearly a year finally got the car tuned, idle is OK…

Here is my problem I got new clutch kit with lighten weight fly–wheel (3.7kg) when it’s idling there’s a vibration (when compare with OEM Clutch kit it's really bad) and rattling sound inside the car; but when I put the clutch down it goes away…
(Crank is Balance with Clutch kit and pulleys, changed Oil, new bearings etc..)

Is this common with lighter flywheel? Will it go away after few KMs?

on a few points....
1) Its the first time running, but you already have had a stock flywheel and clutch on it? While now you have a lightweight flywheel?
2) Clutch down? IF you mean when the clutch is engaged (no foot on clutch) it is noisey, then likely cause is input shaft into transmission....
2a) did you forget idler bearing in crank?
3) you mention crank and clutch was balanced... but nothing about the flywheel... I've found that even a Toda flywheel needs to be balanced

[Animal15]

1): Yes, before i rebuild the motor i had OEM kit. This is First time with light weight flywheel after Tune ;

2): Yeah; clutch is engaged no vibration or sound only at Idling.

2a): I don't think so, Engine Builder install the clutch kit and everything.

3): Sorry everything Balance including Flywheel.
(

I've found that even a Toda flywheel needs to be balanced

I know It's TecArts Clutch kit , i thought they might be well Balance But they are NOT)

[scottreichstein]

could be a dodgy thrust bearing?

[allencr]

...when it’s idling there’s a vibration... ...rattling sound inside... ...when I put the clutch down it goes away…
Is this common with lighter flywheel? Will it go away after few KMs?

Yes, the heavy wheel allowed a slower & smoother idle. Cam and/or compression change?
No. Going away when disengaged from the transmission is a transmission problem, not balance, or it's possibly the clutch disk.

[crownv8]

It may be gear rattle in from the gearbox due to the lightened flywheel causing the engine to spin less smoothly at idle. Remember that is one of the reasons the flywheel is heavy.

Have you changed the gearbox oil lately? That can help if the oil is old and gone thin. Good oil will cushion the gears and minimise the rattle.

[Hurricane]

i just had another read then, so its only vibrating at idle and after that its gone? after idle with and without the clutch engaged or no change at all?
id remove the trans and check the fllywheel, clutch and spigot side of things, make sure the spigot is not suck into the crank to deep.
see how much movment is in the input shaft of the gearbox.
most time ive had/seen a vibration in the gear box ive been able to hear that its a box issue, like it rumbles or chatters.

dan