Gearbox extremely noisy..

[k3nny]

Hey guys,


Pardon me if i ask some really silly questions as im still quite new to my GTR and hoping to learn as much as i can.

Anyhow, my car was recently tuned by Eiichiro of Autoselect japan and then the clutch started slipping.

So i got it changed to the HKS GDMAX twin plate if im not mistaken and now the pedal is really light although the bite point is really small and the clutch is really catchy although im coming around to getting used to it.

The thing is, my mech told me that for the BNR34 GTR gearboxes that is made by Getrag, Getrag reccomends using ATF.

So he used Motul ATF for my tranny and according to him, its normal to be quite noisy. In fact, its noisy under low revs when accelerating around 1000 - 2500rpms.

And sometimes at idle, i can hear a rattling noise from the gearbox which was previously not there.

All the while, my car when it is shut off, there is a slight rattle from the gearbox when i kill the engine and it shudders before it goes off and i came to understand that it is prob from the gearbox mounts being worn off.

The rattle now at idle sounds like this particular sound but continous but goes away if you blip the throttle and keep the revs up.
Only abck at idle does the rattle come.

Does anyone have a similar experience or any feedback to share?

Is there any truth behind using ATF in the Getrag boxes cause its much noisier now and sounds rough so its making me worried..

Thanks a bunch for all the responses in advance!

Appreciate it.

Regards,
Kenny

[nismoman]

dont worry about it mate it,s only due to the clutch being changed,ithink most uprated clutchs cause this noise,i run a hks triple plate in my r34gtr and when it,s on idle it sounds like a bag af spanners but like you say put a few revs on and the noise goes.just a normal gtr problem nothing to worry about NISMOMAN

[impreziv]

twin/triple plate clutches always rattle when you are lightly letting off the clutch. but it should not be happening when your foot is not on the clutch pedal. ill bet the clutch was not aligned properly.

[k3nny]

impreziv & Nismoman: Thanks for your responses guys..

The thing is, i know the metallic rattle that is usually associated with twin plate clutches when you clutch in and let off the clutch but my clutch makes 2 different kind of noises that im worried about.

1. Previously, before changing the clutch, the gearbox would be silent at idle but upon killing the engine, the engine would shudder abit and the gearbox would make and tak tak tak kinda sound when the engine is shuddering.

I thought that to be the gearbox mounts being worn out but now at idle, sometimes this sound continously goes. Then you pile on some revs and it goes away and then it comes back. Is my gearbox gone or should i have it looked at by a specialist as i just went to my general mech who im not too sure has much experience with GTR gearboxes..

2. When accelerating, from rpms 1500 - 2500 onwards, the gearbox sounds loud and rough, like you can hear the metal and gears spinning.

Sometimes even at higher revs but it gets softer as maybe the engine gets louder. hehe.

I asked my mech abt it and he said that he used ATF(Automatic transmission fluid) in my box as Getrag recommends ATF for this particular box. But the downside is that there will be increased noise but he says its ok/normal.

Is this true? As im worried that if its making such noises like metaly kinda sounds when accelerating, does that mean the oil isnt doing its job?

Thanks once again for all the feedback. Hehe.. Really helping to clue in a clueless guy..

[Faz Choudhury]

This used to happen on my 200sx, especially when you turned the engine off. It was the gearbox mountings which needed to be changed as they thread had worn away and was coming loose more and more.

Very minor problem...I wouldn't worry, but get them changed

[k3nny]

Thanks for all the responses guys! Appreciate it..

I know the car is running Motul ATF.

When i depress the clutch, i hear the metallic ringing sound from the clutch that i really dont hear the gearbox.

But about that rattle sound that comes when i kill the car and at idle..

When i blip the throttle abit, initially, meaning the first second or so, the rattle increases intensity with the engine speed as im blipping the throttle on the car.

Could this mean a thrust bearing problem as well?

Thanks again for the responses guys!

[DAN00H]

did you have the flywheel machined at he time of having the clutch changed? was the fork installed securely? was the Attessa line removed fro the back of the box when the clutch was fitted? if so, it will need to be 'bleed' properly (issues with pressure on the transfer clutches)... sorry, don't know the proper oil/fluid for the getrag box, but i would say double check the level - a stock box should not be noisy, if it is - damage is occuring.

[GTRDan]

ATF is thinner then g/box oil, so what happens is the bearings or gears in the box rattle on idle or when killing the engine. Its nothing to worry about, as long as that particular noise disapears when the clutch is depressed or when driving.

[nozza1]

Im having the same noise on my newly purchased getrag.

I have a JUN light weight and balanced flywheel, HELIX five paddle clutch, 'C's short shifter, castol d III trans oil and a nismo titanium gear knob.

Is it just the case that, l have removed all OEM parts and that there is nothing to absorb all the noises being generated via uprated performance parts.

Clutch was fine when first put in, but seems to be, when bed in, a chatter is noticeable and a whizzing is felt and heard when hand is on the gear knob when blipping the accelerator, unnoticeable above 2500rpm.

Is it the thrust bearing l'm feeling, it was new with the box, does it need changing or do you think it may not be installed properly.

P.s Dont know anyone else using a HELIX clutch on a skyline, could it be just that the helix clutch is not suitable for the getrag.( HELIX themselves have no knowledge of HELIX 5 paddle on a gtr)

PLEASE ADVISE!! Thanks in advance. Naz.

[GT-R Glenn]

Theres NO ****EN WAY I would put ATF in a Goddy gearbox.
It will shear way before real gearbox oil will.
It might make for slick shifts and more rwks, but the gearbox will wear out more than twice as fast.


Maybe I should take my own advice and search first


R34 GTR redline gearbox oil

[miragev]

is the 34 getrag box not the same as the 32 33 box ? where you put atf in the transfer box which is connected to the transmission and gearbox oil in the gearbox

atf in the gearbox !!! sounds strange to me ....but then i have no experience of the 34 getrag box ...

[nozza1]

recommended by the godfather himself at rb motorsport.

[GT-R Glenn]

For the second time

R34 GTR redline gearbox oil

[freakazoid3]

I should comment in saying that when rebuilding my vito gearbox (not a gtr gearbox i know but also getrag) I was adviced by a reputable mechanic who does nothing but gearboxes to put ATF in it. He said it help to keep the synchro's alive as in colder climates they tend to wear easily by the thicker gearbox oil. I must say gear changing goes much smoother now compared to what it used to be. But that also has something to do with the box being worn in the first place before revising it But as Glenn states, it is much thinner oil, so not 100%sure if it's any good in teh long run. Although my mechanic clamed that the bux should last upto about 25000km more with the ATF compared to the normal gearbox oil.

[GT-R Glenn]

Yeah, and it appears theres "atf" and theres "atf" .....The atf that can be used has pressure or shear additives, do its not just atf ...
If that makes any sense lol