Knocking Under The Car, Around The Gearbox

[kazuhiko]

Hey Guys,

Got a Fg Sedan manual. Recently noticed a knocking coming from under the car, wondering if you guys have an idea of what it is.

So the story goes, it only happens when taking off in first, only happens below 2krpm, I can feel it like is under the centre console ( I always have my arm resting on it). It doesnt happen in any other gear and doesnt happen in any other rev range sofar. its 5-6 real quick thuds and its only just started happening in the last few days.

Any ideas of what im looking at?

[ms700]

Do FG's run a centre bearing on the tailshaft?

[kazuhiko]

to be honest I have no idea, that why im on here trying to get some sort of idea on what it may be

[Chaos310]

got an exhaust fitted to it? mine knocked on the bolt at the front right of the Gbox cross member. take the washer out from under the head of the bolt and move it to the other side.

[kazuhiko]

So some further info on the car.

I bought it standard, no mods at all. I put on a xr8 intake pretty quickly.

Within the first month of thinking it was my old RX7, I burned out what was already a worn clutch. So I threw in a Malwood clutch with further mods in mind.

The car has 78000km on the clock. Now the reason I think it is the drive shaft is because my brothers R31 back in the day had some sort of a driveshaft issue because it had a hard life on the streets and track. His sounded similar to this, but a lot more violent and was under any kind of load.

As I said, as far as I can tell, with various street testing, it only happens in first gear below 20kmhr giving it throttle. It sounds like its coming from directly under the centre console. I can also clearly feel it.

In the spirit of things, I have recorded it and its attached below. Its doing my head in and im not going to drive the car anymore incase it makes whatever the problem may be, whether it is actually bad or notm until I get it checked out. Being the long weekend, its doing my head in MORE!

Have a listen, turn the speakers up!

Edited 07/06/14 02:35 PM by kazuhiko

[ms700]

Is that the noise at 3 secs?

Sounds like turbo flutter.....

[kazuhiko]

There might be a turkey stuck under there... but yea, at 3 seconds, its definately knocking

Sent from my GT-I9505 using Tapatalk

Edited 07/06/14 04:53 PM by kazuhiko

[Knackers]

Did you ever discover the cause? Sounds similar to something that's happening to me in the last two days

[beauski]

Diff bush

[Knackers]

Cheers. Just stuck my head under the car - it's toast