Clutch and gearbox rattle

[Thuppu]

Now when I did get the exhaust silenced I can hear a lot of clutch and gearbox rattle/chatter. I have alu bushings in the front subframe, the gearbox is mounted to the subframe with hard 034 trackdencity mounts, engine is mounted with really stiff polyurethan mounts and 034 front mount. Is it normal to hear quite big rattle sound from the gearbox when driving with low rpm's like 2000-3000rpm..?

[Lloyd]

Yes if you're running a single mass flywheel.

[Thuppu]

Oh, forgot to mention. Yes, single mass Fidanza alu flywheel and a undamped sinter disc.

[SteveH]

I used to get a lot of rattling at idle and it cleared by 2K rpm. It's probably a lot worse if you have solid mounts all round and a very light flywheel. What clutch friction plate do you have?

[driftin jo]

Caused by single mass light flywheel as it does not damp out the engine pulses
Ay low revs hence the chatter. Once you get up the revs a bit i shuts up.
Did you have the bottom end balanced with the new flywheel as if not this will make it
Worse.

[Lloyd]

Caused by single mass light flywheel as it does not damp out the engine pulses
Ay low revs hence the chatter. Once you get up the revs a bit i shuts up.
Did you have the bottom end balanced with the new flywheel as if not this will make it
Worse.

This is absolutely my experience. I swapped a Spec flywheel for a lightened, matched & balanced 3B steel flywheel. Made a massive difference although still have some (minor) audible gearbox chatter. Can easily live with it now though. Before it was BAD.

[Thuppu]

What clutch friction plate do you have?

The friction plate is a 4-puck undampped sinter and SRE pressure plate.

Caused by single mass light flywheel as it does not damp out the engine pulses
Ay low revs hence the chatter. Once you get up the revs a bit i shuts up.
Did you have the bottom end balanced with the new flywheel as if not this will make it
Worse.

On high rpm's I can't hear anything, only on low... Yes, the bottom end is balanced, all to zero. The flywheel was balanced from factory and the machine shop didn't have to do anything to it.