Drivetrain Rattle

[Daniel R]

Originally Posted by Hayden

Is this a rattle only after the clutch is engaged, or does the assembly sound and feel more like two wobbly plates banging into each other until some power, and revs straighten it all out? Could be input shaft or throwout bearing.

Describe the sound more.

The rattle is only when coming off the clutch and accelerating slowly and it is more pronounced when under a load (ie. uphill).

It is more like your former description of wobbly plates, a clack, clack, clack type of sound and once the clutch is all the way out and we are accelerating it disappears completely.

Also, the throwout bearing was replaced with the clutch a few months ago so that has been ruled out already.

Is that any further help?

Thanks for your reply, Hayden.

[Hayden]

Originally Posted by Daniel R

The rattle is only when coming off the clutch and accelerating slowly and it is more pronounced when under a load (ie. uphill).

It is more like your former description of wobbly plates, a clack, clack, clack type of sound and once the clutch is all the way out and we are accelerating it disappears completely.

Also, the throwout bearing was replaced with the clutch a few months ago so that has been ruled out already.

Is that any further help?

Thanks for your reply, Hayden.

When you replaced the clutch, was the pilot bearing also addressed?

The noise was there prior to the new clutch, correct?

When the car is warm, at idle, is there a significant change in noise when the clutch is depressed? The single mass flywheels might amplify this effect, so might not be as useful for diagnosis, especially since the throwout bearing was replaced.

Time to look at the input shaft/pilot bearing side in my opinion, but please keep in mind that I'm not as experienced or knowledgeable with this car as most on here. You said all suggestions appreciated Maybe this will bump the thread and get noticed by someone who can help more. Best of luck!

[Daniel R]

Originally Posted by Hayden

When you replaced the clutch, was the pilot bearing also addressed?

The noise was there prior to the new clutch, correct?

When the car is warm, at idle, is there a significant change in noise when the clutch is depressed? The single mass flywheels might amplify this effect, so might not be as useful for diagnosis, especially since the throwout bearing was replaced.

Time to look at the input shaft/pilot bearing side in my opinion, but please keep in mind that I'm not as experienced or knowledgeable with this car as most on here. You said all suggestions appreciated Maybe this will bump the thread and get noticed by someone who can help more. Best of luck!

Do you mean whilst stationary? Clutch in or out when in neutral makes no appreciable difference, maybe very slightly although I would put this down to the sprung clutch, it is barely perceivable.

The only thing you've mentioned that resonates is that this problem is much more noticeable when the car is warm.

Just a thought, if the inner CV joint/s were failing could this be a cause?

I am getting desperate to solve this problem as it affects the drivability enough to become a real nuisance and I have already spent quite a bit of money replacing "the usual suspects" only to find that nothing has changed.

Thanks again for your help, it is much appreciated.

[woodsman]

Is the clutch disc a high-friction/HD/long-lasting, sprung type? Mine is and after I've been in stop and go traffic for a bit, something starts to 'hop and bang' as I'm nearing full release. I've attributed this to the high- friction, long lasting, sprung disc and high force, pressure plate. It disappears if I purposely ride the clutch. It never does it when the car's cold. I've also observed that when it's occurring, I am failing to release the clutch. Why? Because the car will catapult forward in a neck-snapping fashion or it will stall. SO what I'm missing is a little slip while 'things' synchronize to the same speeds. I have a 'Grabby clutch' because it's designed for circumstances outside of the OEM design parameters. Hence the nasty behaviour. I WAS going to turbo my car. Same problem or not?

[Daniel R]

Originally Posted by woodsman

Is the clutch disc a high-friction/HD/long-lasting, sprung type? Mine is and after I've been in stop and go traffic for a bit, something starts to 'hop and bang' as I'm nearing full release. I've attributed this to the high- friction, long lasting, sprung disc and high force, pressure plate. It disappears if I purposely ride the clutch. It never does it when the car's cold. I've also observed that when it's occurring, I am failing to release the clutch. Why? Because the car will catapult forward in a neck-snapping fashion or it will stall. SO what I'm missing is a little slip while 'things' synchronize to the same speeds. I have a 'Grabby clutch' because it's designed for circumstances outside of the OEM design parameters. Hence the nasty behaviour. I WAS going to turbo my car. Same problem or not?

I'm tempted to say yes, as I too have what I suspect to be a very similar setup to you. The only difference is that this noise was EXACTLY the same with the OEM dual-mass flywheel and solid clutch setup. It is true that riding the clutch stops the noise, if I give it some gas up to 2k rpm then come off slowly the noise is gone or at least greatly subdued. My theory on this is that there is something loose somewhere which gives driveline play and a progressive application of torque keeps things at an extreme in the range of play. When the clutch is slipping at semi-engagement the torque is not progressive and it causes the component that has some play in it to bounce around between the maximum and minimum range of play, hence the noise as it bounces back and forth.

I hope that my explanation can be understood, I am not a mechanic or an engineer so please forgive my poor attempt.

The question really is what can be causing that much play in the drivetrain?