Rattling when driven, goes away when clutch is pressed down

[Lupo Tom Lupo]

Hi guys,

Title says it, made another thread not too long ago but think I'd written it in a confusing manner.

I've done some Googling and read that people tend to say that driving along with a bad rattle which goes away when you put the clutch down to the floor is caused by a bad release bearing, however, when I've spoke to a clutch and flywheel specific garage and another garage they've said it's the complete opposite and if it goes away when you pull the clutch in it's likely the gearbox.

It's frustrating because people have the same symptoms and all seem to say it's the release bearing so I don't understand why the mechanics are saying everyone's wrong, help?

Thanks

[Sausage]

Clutch isnt either on or off so try some detective work on when the noise changes. At light touch on the pedal? At the bite point? At clutch released? Same thing coming back up the pedal travel from the floor.

Release bearing isnt doing anything until you touch the pedal and move it into contact with the pressure plate. As you press the clutch in it is then under load and will make noise if it is worn. That will be a rotational scraping noise. A rattle there might be broken release bearing mount, broken clutch finger etc but will sound horrendous.

If your rattle is coming in at the clutch bite point and then disappearing on clutch pedal down beyond bite point (clutch disengaged) then that is when input shaft on the gearbox starts and stops rotating. If so then gearbox.

Edited June 24, 2019 by Sausage

[Lupo Tom Lupo]

Ah, I've clearly been reading stuff from people who don't know what they're talking about then @Sausage, if I were to get a new (used) gearbox would I have to get the right gearbox code or would any gearbox from a 1.4 Lupo (75 bhp) / 1.4 Polo (75bhp) fit properly?

[Pete]

Tbf more often than not when I’ve coming across an idle rattle like this it’s either been the dmf falling to bits or the release bearing.

[Sausage]

Yep, other variables are clutch not adjusted right so release bearing is always under some load or clutch faults.

Input shaft spins in neutral at clutch bite point, so you can hear excessive bearing noise or rattles then if it has problem. If it only rattles when the car is moving then output shaft, differential side of things comes into play.

Edited June 24, 2019 by Sausage