Skyline Gearboxes Query! Help

[JIMMY R]

Hey I'v got an R33 GTST, iv recently got my gearbox Recond. now before i got it recond When in Neutral in Idle it would make a noise like a bearing sought of sound, but then wen u push the clutch in it'll go quiet!! after the recon it still continued to hav this noise, the mechanic said "yeh its still gonna make some noise as wen in neutral the skyline gearboxes still have moving parts operating in idle".

my question is: is this true and is this normal for all skylines including mine?

i know sound like a stupid question, but i just want to satisfy myself in knowing that i didn't waist time and money and the problem still stands.

Thanks guys

[Smurf]

Not sure about the mechanics of it all however my car has the same sound. Took it to a mechanic who new nothing about skylines who said that it would not be an issue.

[towlie]

Think it may be time to look for a new mechanic. I've got the same issue and two different mechanics, one being a clutch specialist within a minute of hearing it said it was an issue with the thrust bearing on the clutch. When you place a slight load on the bearing by pressing the pedal the noise disappears. Don't ask me to get more technical than that I'm just telling it like I heard it. If it's the same thing then I was told it's not a problem unless the noise starts to really get to you then you can replace the clutch otherwise to leave it till it needs replacing anyway, but I like my thousand bucks more than the sound (even if it is embarrassing having a sports car sound like a cricket).

[JIMMY R]

thanks guys, it sounds like its a universal problem among the skylines but the thing is, i have got the bloody gearbox recond, new bearings everything. if the moving parts theory from the mechanic is tru then its not a problem, but as u said about the thrust... would'v it hav been replaced....i wonder these days wen u pay for things to be done to the car and crap is done instead !...

Edited October 7, 2007 by JIMMY R

[bigslick]

I'm no gearbox expert, but I do know that even in neutral, with your foot off the clutch (therefore the clutch plate engaged to flywheel), the front shaft in the gearbox is spinning. Basically all gearboxes are the same. It sounds like the thrust bearing, which is something you replace when doing the clutch, not necessarily a gearbox reconditioning, or it can be done by itself if it's really a problem cos it will still involve removing the gearbox obviously.

[JIMMY R]

I'm no gearbox expert, but I do know that even in neutral, with your foot off the clutch (therefore the clutch plate engaged to flywheel), the front shaft in the gearbox is spinning. Basically all gearboxes are the same. It sounds like the thrust bearing, which is something you replace when doing the clutch, not necessarily a gearbox reconditioning, or it can be done by itself if it's really a problem cos it will still involve removing the gearbox obviously.

cheers bigslick, see the thing is i got a new clutch wen i got the gearbox recond. its just a first stage H/Duty Xtreme one. but no matter!! the mechanic should've changed the thrust bearings wen doing the clutch? i guess i need to pay him a visit. but my question is it normal for the skyline's R33 to sound like that while in neutral even if the front shaft is spinning?

[bigslick]

No it's not normal. Yes the thrust bearing should have been changed. Get a second opinion from another mechanic. If he says it definitely sounds like the thrust bearing, then go back to the first one and demand to know why it wasn't changed when the clutch was done.

[wrxhoon]

Sounds like the main shaft bearing , it goes away when you push the clutch in because it stops spinning then . The thrust bearing should be noisy when you push the clutch in ( if its stuffed ) because thats when its under load .

[turboedsloth]

the throw out bearing makes a noise when its disengaged. its because theres either a bit of crap in the bearing or its running dry because it wasnt greased properly. a thrust bearing comes in the clutch kit or at least one should as its supposed to be replaced with the clutch. as for the inner workings of the gearbox, with the clutch pedal out the input shaft is turning which is also turning the cluster shaft along with all the actual gears as they run on bearings, the cluster shaft throws oil around lubricating everything so it doesnt seize, when you push the clutch in it slows the input shaft down so you can select a gear easier. the selector hubs are splined onto the output shaft and only move back an forth when you move the selector. the cluster bearings and input bearings mainly make noise in 1st,2nd,3rd and 5th when under load. in 4th there isnt much load as it all goes straight through the input shaft out the output shaft instead of going through the cluster aswell. hope this sorta helps

[BHDave]

wrxhoon is correct, turbosloth seems very confused, everyone who said thrust bearing is plain wrong.

for reference, thrust and throw out bearing are different terminology for the same bearing, turbosloth is confusing the spigot bush/bearing with throw out bearing. And all gears have to run though the lay shaft as you have a separate input and output shaft and they have to be connected some how for the box to work.

So to answer the original question, yes, the input shaft will be rotating and thats why you han hear the bearings. If you have good condition gearbox mounts and sound deadening still installed, along with all boots and a stock shifter you should barely hear it. Nissan puts in a lot of work to reduce NVH in these cars. If you have an aftermarket shifter you will almost certainly hear it.

If it's noisey as f**k, then i'd get confirmation that all the bearings were changed when the box was recoed.

[Links]

Agree with Wrx and BHDave, sounds like you've got an issue with the input shaft bearing or main bearing as this will be spinning when in neutral with the clutch engaged.. As soon as you put the clutch in it will stop spinning..

If you just got it reconditioned and it's bugging you take it back to them.. Depends on how loud it is..

[turboedsloth]

4th gear just goes straight through the gearset as the selector hub connects the input an output shaft together hence why the ratio is usually 1:1

[wrxhoon]

4th gear just goes straight through the gearset as the selector hub connects the input an output shaft together hence why the ratio is usually 1:1

Makes no difference what gear its in, even in neutral the main shaft ( or input shaft) still turns as long as the clutch is not pushed in , when the clutch is pushed in then the main shaft stops and he said the noise goes away then . this is where I based my diagnosis that sounds like main shaft bearing .

[JIMMY R]

ok thnks fellas, i'll go investigate but as wrx hoon said, probably the main shaft bearing is the one. but the thing thats pisses me off is that shouldn't it hav been changed wen i got the box recond, or at least checked and then brought to my attention. See these days u really hav to go to someone who knows what the hell their doing and looking for.

cheers

[JIMMY R]

just quickly if i install one of those NISMO short shifters, how will that effect the gearbox running and or noise etc. will it cause any long term damage etc...

[Cubes]

Yes the input/main shaft bearing should have been changed.

You will always get a 'slightly' noise when in neutral BUT not loud enough for you to hear it unless your in a shed and really listening for it with the door open and your head down near the ground.

If you can hear it with your window open sitting in the car without walls around you then either something has gone wrong with setting clearances OR they didn't bother changing it.

Was it a full complete rebuild or did he just replace what was thought to be worn? The price difference varies between the two.

[superspit]

Yes the input/main shaft bearing should have been changed.

You will always get a 'slightly' noise when in neutral BUT not loud enough for you to hear it unless your in a shed and really listening for it with the door open and your head down near the ground.

If you can hear it with your window open sitting in the car without walls around you then either something has gone wrong with setting clearances OR they didn't bother changing it.

Was it a full complete rebuild or did he just replace what was thought to be worn? The price difference varies between the two.

Dang!....just took my 2003 V35 (6 speed) for it's first long drive tonite.....put it back in the carport (fences either side) and man...the 'bearing' noise was there...clutch in..noise gone and nice and quiet.

Revved the engine (clutch out) and it rattled for a second as it settled back to idle speed....

Clutch in, revved, and beautiful and quiet again as she settled back to idle speed....

Spigot bearing or thrust bearing guys????....daaaaang!!!

I'm going to go back to the seller soon, with this issue..(paid $1980 for a years warranty, though she ain't broke yet!))..I'm really upset by this shit...only just had the car a week!....other than that, she's gorgeous...only done 30,000K's!

[madbung]

I'd be very suprised if it isn't the thrust bearing..

As already stated "its running dry because it wasnt greased properly" If i've seen it once i've seen it 1000 times.

[skylinekid]

god sum ppl really are stupid!!!!

when clutch is out nor the throwout bearing or the spigot bush/bearing is in use and they are doin the same speed as the engine. therefore the only bearing that is spinning that would be most likely to hear would be the input shaft bearing.... when clutch is pushed in if the noise was a spigot or throwout this is the tim u would be hearing it. due to the fact of the clutch has released drive between the input shaft and crankshaft. think about it ppl go through things in ur mind first b4 u start telling ppl wat u think the problem might be.

Edited December 23, 2008 by skylinekid

[superspit]

soz...