I had gearbox changed and the fitter did ask if we are changing release bearing at same time. I left the old one in as I did not know if you can put any other brand in as it' a helix clutch.

Anyway two months down the line there is a slight chatter noise which came on the first days of the cold weather. rpm related and only in neural. goes away when clutch pressed.

Also goes away 100% when in gear and driving. I know there is exhaust/ wind noise etc. but I've gone through underground carpark, tunnels and there is zero noise when in gear.

So is this gearbox neutral shaft play if there is such thing?

I gave the guys new gearbox oil.Castrol but gave them about 2.7.2.8 litres. Thinking of putting some fuschs titan instead now. (3 bottles of 1 litre)

It sounds like it is a clutch release bearing. Compare new with old with clutch release bearings. I have not seen major differences with bearings. A small amount of noise is OK. Mine is about six months old and there is slight noise. If it screams at you, then that is the time to be concerned. Always change bearings when you change a clutch. The 4&5 (084/5) speed Mk 2 gearboxes use synthetic. The 084 I have rebuilt is silent. Is your new gearbox rebuilt with a guarantee? In neutral the primary gearbox will spin with the clutch out so the bearings for that shaft will also revolve so if the bearings are worn they may be noisy in neutral. I am presuming a 6N gearbox will be similar.

Regards Phil

Think about it for a sec, if a clutch release bearing is worn to the point that its noisy, then pressing the clutch puts the release bearing in contact with the clutch plate fingers and spins. If this makes a noise then yes, your release bearing is shot.

In your example, the noise exists when the release bearing isn't actually spinning (or at least it shouldn't be) as there is a clearance between the release bearing and the clutch plate fingers with the pedal released.

This all means that more than likely you have a bearing fault on your gearbox input shaft, as it stops entirely spinning with the clutch on the floor, but will of course be spinning with the clutch out, even in neutral.

Make sense?

That depends of the model of car tho, a lot of cars have the release bearing constantly in contact with the clutch plate these days and it will be noiser with the clutch up.

If this is a 6n then my bet would be release bearing

Can't see a release bearing lasting say 100k of constant rotation, not to mention the fact that its the same release bearing as a mk1/2 which definitely has clearance specified to prevent this.

Its only a greased, sealed roller bearing.

Mk 2/2f are the old school no contact but Yeah I agree it does sound like a bad idea but most cars now have a constant contact bearing.

I was told it was because it's was deemed easier on the bearing if it was running constantly but with next too no load rather than stationery and suddenly have to hit 7k rpm at high rpm changes.

My 6n2 has a similar problem to OP, except that I have chatter noise when driving in gear in addition to when the car is in neutral.

This noise goes away when any pressure is applied to the clutch pedal.

What Vic said first makes sense to me; the clutch in means the gearbox input shaft stops spinning and the noise goes away. Therefore, the problem lies with the input shaft.

However, my problem is that the same noise is there when driving in gear. Does the input shaft continue spinning when the car is in gear?

Think about it for a sec, if a clutch release bearing is worn to the point that its noisy, then pressing the clutch puts the release bearing in contact with the clutch plate fingers and spins. If this makes a noise then yes, your release bearing is shot.

In your example, the noise exists when the release bearing isn't actually spinning (or at least it shouldn't be) as there is a clearance between the release bearing and the clutch plate fingers with the pedal released.

This all means that more than likely you have a bearing fault on your gearbox input shaft, as it stops entirely spinning with the clutch on the floor, but will of course be spinning with the clutch out, even in neutral.

Make sense?

It tends to be that when pressure is off the bearing it rattles about making it noisy when the bearing is worn, when you put pressure on the bearing it can't rattle about so little to no noise. The release bearing will still be sitting against the pressure plate and spinning with the clutch depressed. There shouldn't be clearance between the bearing and the pressure plate, that's why if you try and push the clutch arm back with your hand you won't do it, if there was clearance you could. Instead you need to lever it because you are pushing against the pressure plate.

I've always found noisy release bearing stop being noisy when the clutch is pressed.

Edited 2 February, 201610 yr by Mclovin

The clearance I'm talking about is the first 5mm or so travel of the clutch arm before the release bearing hits the clutch pressure plate fingers.

Uneven gravilly rattle that slowly reduces as pedal is slowly pressed... in my experiance (so far) has always been release bearing.

Edited 3 February, 201610 yr by kbs

Yep. also if I press it a few times it just goes away completely. seems like a adjustment has gone wrong.

then drive it a bit . come to a stand . put in neutral and off it goes again, chattering away . not too loud of course.

Are all release bearing compatible? Have helix organic road clutch.

When you had the gearbox fitted, did they check the sleeve over the input shaft where the release bearing slides?

Well I gave them a new one to put on.

Did you ever get to the bottom of this? I've got the same and thing release or gearbox bearing