Hi, can anyone help to try and diagnose this noise.

I appreciate there will be some guessing, but maybe someone has had this and can say with more confidence?

This rattle only occurs at around 1200RPM, by 1500RPM its gone.

It only happens under load in any gear, for example turning on to a side street leaving the car in 3rd and then applying some gas. As it passes thru this rev range it rattles like this.

The video shows car on stands in 4th gear using handbrake to labour engine at 1200rpm

I suspect propshaft (one piece item) or a gearbox issue?

It is not heat shields or cats. It doesn't make the noise during over run, in neutral or any other scenario.

Any other ideas appreciated!:)

 

Hi, can anyone help to try and diagnose this noise.

I appreciate there will be some guessing, but maybe someone has had this and can say with more confidence?

This rattle only occurs at around 1200RPM, by 1500RPM its gone.

It only happens under load in any gear, for example turning on to a side street leaving the car in 3rd and then applying some gas. As it passes thru this rev range it rattles like this.

The video shows car on stands in 4th gear using handbrake to labour engine at 1200rpm

I suspect propshaft (one piece item) or a gearbox issue?

It is not heat shields or cats. It doesn't make the noise during over run, in neutral or any other scenario.

Any other ideas appreciated!:)

 

Check condition of your differential and subframe bushes.

 

Mine does this, but the rear subframe bushes are almost non existent. Replacing them next month which should cure it.

Check condition of your differential and subframe bushes.

 

Mine does this, but the rear subframe bushes are almost non existent. Replacing them next month which should cure it.

Its an idea, but TBH the noise is very central to the car and doesn't appear to be from the rear end.

Its an idea, but TBH the noise is very central to the car and doesn't appear to be from the rear end.

Almost all manual zeds I have driven ( many) do this noise such as when turning into a side road or changing from 1st to second gear and as you said once driven through stops.

 

The clutch fork is often ( but not always ) the culprit as it only occurs as the pressure comes off the fork and this will be worse with a missing or worn fork gaiter where it enters the gearbox. The fork acts on the bearing carrier and both the fork and the carrier wear and this can lead to the harmonic rattle as well as other issue`s with clutch judder or even poor selection

 

Unfortunately its box out to change them both.

 

Did a thread about the fork issue with wear some time ago, check out the link http://www.300zx.co.uk/forums/showthread.php?145251-Nice-clutch-tech-thread&highlight=clutch+fork+tech

 

 

Jeff TT

Edited September 23, 201411 yr by JeffTT

Almost all manual zeds I have driven ( many) do this noise such as when turning into a side road or changing from 1st to second gear and as you said once driven through stops.

 

The clutch fork is often ( but not always ) the culprit as it only occurs as the pressure comes off the fork and this will be worse with a missing or worn fork gaiter where it enters the gearbox. The fork acts on the bearing carrier and both the fork and the carrier wear and this can lead to the harmonic rattle as well as other issue`s with clutch judder or even poor selection

 

Unfortunately its box out to change them both.

 

Did a thread about the fork issue with wear some time ago, check out the link http://www.300zx.co.uk/forums/showthread.php?145251-Nice-clutch-tech-thread&highlight=clutch+fork+tech

 

 

Jeff TT

Edited September 23, 201411 yr by JeffTT

Thanks Jeff. Would it still make the noise even if the clutch pedal is fully released? This noise occurs with the clutch fully engaged, pedal fully released, not during release if you understand. Any time the engine is labouring at these revs in any gear.

I appear to have the exact same noise! Had it ever since I bought my zed. Grrr!!

I appear to have the exact same noise! Had it ever since I bought my zed. Grrr!!

 

Ok, please tell me what you've done so far that hasn't cured the problem!:(

Its not causing any real problem other than it sounds pants and spoils the driving experience!

Thanks Jeff. Would it still make the noise even if the clutch pedal is fully released? This noise occurs with the clutch fully engaged, pedal fully released, not during release if you understand. Any time the engine is labouring at these revs in any gear.

 

The Clutch bearing still hits the clutching housing forks, thus will still rotate, i have the same noise. which i shouldn't have in all honesty having had the gearbox off 3 times so far and replaced the fork and bearings once in all that. Its just a zed thing. mine could be down to the pivot ball (cant remember its proper name) wearing, im struggling to get the car into 3rd and 4th with out grinding sometimes. im putting this down to as i said before, the wear on that pivot ball for the clutch fork which means my fork sits slightly (and i mean ever so slightly) further back into the gearbox. hence why i get the rattle and gear selection issue. first takes a bit of convincing as well, but that doesnt grind the syncros.

Mark Derby told me it's a manual zed thing too. Mine does it under load any gear below 2000rpm. Like an over torque shingle. I never do it but when other people drive my car they seemingly go totally deaf and rattle and short shift the full journey, "pack it in! Change down you crackpot!"

I've always wondered what was causing this ever since I picked this Zed up 3 years ago, finally the answer!

 

My car doesn't have that constant rattle, just when changing from first to second you can get the clunk, also if going very slowly can happen as well on bumpy roads.

 

Not much to be done about it though it seems best to just live with the annoyance.

 

My first Zed didn't do this, but I remember being told that the clutch fork had previously snapped and been welded, I wonder if something done during that welding fix solved it.

Edited September 24, 201411 yr by Dazsw