cluch noise

Could be the thrust brg, also consider the input brg too. When in neutral it still spins with the engine rpm. Also can be other factors too but they seem to be the most common.
Ange

Odds on - it's the primary shaft bearing at the front of the gearbox. This shaft spins even when you're in neutral, no gear selected and your foot is OFF the clutch pedal. However, it stops spinning when you depress the clutch pedal.

Next best bet - IF there is a needle roller bearing located in the primary shaft where it meets the main drive shaft that supports the 'fat' end of the primary shaft, it could the needle roller bearing. But doubtful - needle bearings generally don't whine and they are nowhere as big as the primary shaft bearing.

Next,next,best bet - IF there is a needle roller bearing located in the flywheel that supports the 'thin' end of the primary shaft, it could the needle roller bearing. But doubtful.

Next,next,next best bet - I don't reckon it's the clutch thrust bearing. This bearing is stationary when your foot is OFF the clutch pedal. It only rotates when your the clutch pedal is depressed. Unless it's been adjusted up really tight to the clutch pressure plate thrust pad. (Unusual for this to be the case)

All of this must be as "depressing" as the clutch pedal itself - 'cos to fix the noise, the gearbox has to come out and it's usual to replace all bearings whilst the box is out - oh and put a new clutch in.

Bilbo

All gears spin when clutch is out in neutral except the reverse idler. It could be bearings or it could be just a gear whine, has this noise just started your have you just noticed it. When driving is the noise there through all the gears except 4th. For an easy solution on diagnosing the prob just go to a few work shops and get a quote.

Wash a drain tin out and drain the gearbox oil into it. If the input bearing is noisy there should be a silvery tinge to the oil.

Hi mate,
I can't help but think that other posts are looking to deep to early.Bottom line is you have a noise that needs to be fixed. I think that it's just your thrust bearing. If you don,t do anything it will let go, you just can,t pick when or where.
My advice (for what its worth) remove the gearbox and inspect the thrust BRG.It will be obvious if it has dryed out/worn/failed. If it is OK then look further then. If its shot, Fit a new clutch kit and you,re away.
If you are unable to do the work yourself Make sure that you tell the repairer not to proceed to the next step without your OK.
Cheers Nino.