This is on the missus's 1.2 with GSB code 02T gearbox.  166k on the odo.

 

I think it's been getting very gradually noisier over quite a long while (like a year or two), but it's only recently got to the point of sounding intrusive.

I took a video a week or two back, but can't post it from here, will add later. Imagine an insistent, very shrill bird that cheeps almost at the top limit of your frequency spectrum. Only audible at relatively low speeds (up to 40, say) , I guess drowned out by other noises above that.

 

Then imagine that the bird is sitting right under the clutch pedal, and when you stomp on the pedal the noise disappears...But seconds later, after releasing the pedal, the little bugger recovers and starts up again...

 

Presumably that makes it a bearing somewhere inside the gearbox?

 

I think the influence of the clutch pedal means it can't be anything engine side, but tempted to whip off the aux belt and run it briefly just to be 100% sure.

 

Any experience? Advice?

 

Ta.

 

Edited 15 April, 20197 yr by Wino

I think you replaced the clutch a few years ago? Was the same noise there before that?

No, this is newer than that.

Only in the last few months have I noticed the high-pitched cheep. I think there was a noise before this (and even before the clutch change, more than 2 years ago now), but more of a quiet 'churn' that didn't sound too concerning, to my untrained ears. 

Neither were/are noises my Polo makes, but wasn't sure if it was related to the timing chain, maybe, on the Fabia. I never thought back then to experiment with clutch down/up.

 

Edited 17 April, 20197 yr by Wino

So the noise is only when moving, it does it in any gear and when you dip the clutch the noise goes?

Just now, SuperbTWM said:

So the noise is only when moving, it does it in any gear and when you dip the clutch the noise goes?

 

Not sure about the only when moving aspect. Can check in about half an hour or so if it does it at a standstill, in neutral.  Pretty sure it does.

I would say its probably not the gearbox, dipping the clutch at speed disconnects the engine but the gearbox would still be spinning as usual presuming you left it in gear so the fact that is stops when you press the clutch means it must be something else.

 

Trouble is, like you say, if the clutch affects it, it looks like its nothing engine related either. It could be something in the bell housing but the thrust bearing only makes contact and spins when the clutch is pressed doesn't it? so it can't be that.

 

Very strange

Edited 15 April, 20197 yr by SuperbTWM

Thanks. 

I did recently remove and re-grease the idler pulley of the aux belt run, but that made no difference at all. Thought it sounded a bit rough, and it was pretty dry, but it clearly wasn't that.

 

With a stethoscope poked around the place (around the same time as I took the vid), the noise is loudest on the top of the gearbox housing, but also present near the crank pulley.  Come to think of it, all that must have been observed in neutral, at a standstill.  Just need to experiment to see if dipping the clutch in that condition makes it disappear too. If it remains I guess I can then see if it's still there at each location, with an assistant holding down the pedal.

The cheep/chirp does go away when the clutch is floored, even in neutral at idle. Returns when clutch pedal is released.

 

Here's the video taken a month or so back.  Try to ignore the general sewing-machine clatter, that's 'normal' for these engines, it's the high-pitched 'cheep' that is recent, and loud enough now for the missus to be complaining about it when the radio isn't on.

 

https://www.dropbox.com/s/qexlz3ih5i8gq7k/20190309_162038.mp4?dl=0

 

This vid was taken a few minutes ago, maybe a little louder on the cheeepiness?

 

https://www.dropbox.com/s/j5apy22b3v1269h/20190415_171454.mp4?dl=0

Edited 15 April, 20197 yr by Wino

36 minutes ago, SuperbTWM said:

 but the thrust bearing only makes contact and spins when the clutch is pressed doesn't it? so it can't be that.

 

 

 

Although the release bearing isn't doing much when the clutch pedal is not pressed I'm pretty sure they are still in contact with the pressure plate and are spinning without load.

Hmmm, the noise on the video doesn't really sound like release bearing noise.

I think I've read about the bearings at the outboard end of the gearbox shafts on the 02T being troublesome, could it be the input shaft part of that? 

It seems too high pitched for it to be an oil-lubed bearing though, which those presumably are? Or are they?

To me it sounds like something horribly dry. I wouldn't think that gearbox bearings would sound like that.

33 minutes ago, TMB said:

 

Although the release bearing isn't doing much when the clutch pedal is not pressed I'm pretty sure they are still in contact with the pressure plate and are spinning without load.

 

I'm not 100% either, I think some arrangements do and some don't. On the VAG design I thought it sat on the fingers of the pressure plate so would normally not be touching the friction plate

 

@Wino does the clutch have to be fully disengaged to stop the noise or does gentle pressure on the pedal make it go away. If you apply enough pressure to load up the thrust bearing but not fully disengage the clutch we can probably rule out the thrust bearing at least

Edited 15 April, 20197 yr by SuperbTWM

It is the primary shaft bearings 100%. It only stops spinning when clutch pedal is pressed.

42 minutes ago, SuperbTWM said:

 

 On the VAG design I thought it sat on the fingers of the pressure plate so would normally not be touching the friction plate

 

 

It's the same thing. The fingers are part of the pressure plate and are rotating. The release bearing never touches the friction disc.

Edited 15 April, 20197 yr by TMB

18 minutes ago, RicardoM said:

It is the primary shaft bearings 100%. It only stops spinning when clutch pedal is pressed.

 

I would think that too if it wasn't a squeaky, dry sort of sound. Primary shaft bearings ususally rumble or make a rough sort of sound.

9 minutes ago, TMB said:

 

I would think that too if it wasn't a squeaky, dry sort of sound. Primary shaft bearings ususally rumble or make a rough sort of sound.

 

They also knock out the oil seal when they fail leading to gearbox oil leakage.

11 minutes ago, sepulchrave said:

 

They also knock out the oil seal when they fail leading to gearbox oil leakage.

 

OK well that might explain it if that's what's happened. Can't say I've ever come across that myself. I would have thought that Wino would have noticed oil leaking from the bellhousing.

Edited 15 April, 20197 yr by TMB

15 minutes ago, TMB said:

 

OK well that might explain it if that's what's happened. Can't say I've ever come across that myself. I would have thought that Wino would have noticed oil leaking from the bellhousing.

 

No, I'm agreeing with you that it's not likely to be the input shaft bearing.

Ah ok. Got you now.

Edited 15 April, 20197 yr by TMB

52 minutes ago, TMB said:

 

It's the same thing. The fingers are part of the pressure plate and are rotating. The release bearing never touches the friction disc.

 

Of course it does, bit of a brain fart there on my part !

Edited 15 April, 20197 yr by SuperbTWM

Just now, SuperbTWM said:

 

Of course it does, bit of a brain fart there!

 

Happens to us all

Will check for oil loss but I think the recent MOT would've mentioned that. 

Think I might get a cheap lower-mileage ebay box to sit on the shelf pending more drastic failure, or if I get really keen, an Easter treat swap-out.

@Wino

I think you're probably looking at this kit for repair.

This and this might help.

 Ricardo, thanks.  I probably could do all that, but knowing me (painfully slow) it might take me several full days work, so I think I'd better either buy a refurbished one, or gamble on a secondhand one 'as is'.

 

That SSP is very interesting. Thanks again.

 

Edited 16 April, 20197 yr by Wino