Gearbox on its way out?
Discussion
My gearbox makes a whum whum whum noise, like a wheel bearing but quieter. It happens in any gear, at any speed wether I be on power or on the overrun, though it does go away if I dip the clutch or put the car into neutural.
Now its not really a problem, more like an inconvinence, but is it a sign of worse things to come? 6 speed box by the way, changed the oil 6,000 miles ago, whats the chances it could have knackered the box?
Now its not really a problem, more like an inconvinence, but is it a sign of worse things to come? 6 speed box by the way, changed the oil 6,000 miles ago, whats the chances it could have knackered the box?
Its hard to tell, quite possibly, but its drowned out once the engine revs start getting above 2.5k.
You can't really hear it at 20mph, but you can at 30mph, 40mph or above its drained out by the road & tyre noise. Sat at 30mph, the noise reminds the same regardless of what gear I select.
So what parts of the box stop turning when you dip the clutch?
You can't really hear it at 20mph, but you can at 30mph, 40mph or above its drained out by the road & tyre noise. Sat at 30mph, the noise reminds the same regardless of what gear I select.
So what parts of the box stop turning when you dip the clutch?
Edited by BigMonk on Sunday 4th October 08:28
Yes open diff, but wouldn't the diff continue turning despite the clutch being dipped, and hence make the noise regardless what the car is doing?
My friend had a diff go on his 5 speed, and that made an awful noise regardless of the gear / clutch / power on or off, and it got worse going round corners.
My friend had a diff go on his 5 speed, and that made an awful noise regardless of the gear / clutch / power on or off, and it got worse going round corners.
I was thinking a bearing of some sort as it definately sounds like one. I'm not too clued up on gearboxes, can you explain further what a thrust bearing is, is it serious and does it mean a new box is required?
Edit: A quick google search reveals a throw out bearing is part of the clutch?
Edit: A quick google search reveals a throw out bearing is part of the clutch?
Edited by BigMonk on Sunday 4th October 10:52
The thrust bearing acts on the clutch plate
It is a 'throw out' bearing, sometimes called the clutch release bearing. Allowing the engagement and disengagement of the clutch. Not an integral part of the gearbox, but located on he transmission shaft between the box and the clutch. Can be changed separately, but usually comes with a new clutch kit.
It is a 'throw out' bearing, sometimes called the clutch release bearing. Allowing the engagement and disengagement of the clutch. Not an integral part of the gearbox, but located on he transmission shaft between the box and the clutch. Can be changed separately, but usually comes with a new clutch kit.
Edited by Stella Artois on Sunday 4th October 10:56
Interesting, thing that strikes me is the drivetrain is smooth and as far as I can tell.
Apparently the thrust bearing can become dry and make a whum, but doesnt actually cause a problem in itself? On another note, if it was the throw out bearing / clutch release bearing, wouldn't the noise happen while stationary?
Apparently the thrust bearing can become dry and make a whum, but doesnt actually cause a problem in itself? On another note, if it was the throw out bearing / clutch release bearing, wouldn't the noise happen while stationary?
Edited by BigMonk on Sunday 4th October 11:24
If the thrust bearing were to become worn or seized it can cause damage to the paddles on the clutch unit (fingers in the 2nd picture) if sufficient damage is caused to these paddles/fingers the clutch unit can fail. Meaning you will start to have difficulty in engaging gear. Not sure with the MTX75 Gearbox, but a large amount of gearboxes have an access hole that allows you to connect the thrust bearing lever (which is attached to your clutch cable or hydraulic actuator). You 'should' be able to see if the thrust bearing is operating smoothly along the gearbox shaft (However, with the floor and panels on the noble, this my prove difficult/impossible)
Stella Artois said:
If the thrust bearing were to become worn or seized it can cause damage to the paddles on the clutch unit (fingers in the 2nd picture) if sufficient damage is caused to these paddles/fingers the clutch unit can fail. Meaning you will start to have difficulty in engaging gear. Not sure with the MTX75 Gearbox, but a large amount of gearboxes have an access hole that allows you to connect the thrust bearing lever (which is attached to your clutch cable or hydraulic actuator). You 'should' be able to see if the thrust bearing is operating smoothly along the gearbox shaft (However, with the floor and panels on the noble, this my prove difficult/impossible)
No problems engaging gears, but if I'm smooth with second it some times pops out when I apply power. I would say it started to happen about the same time as the whumming noise, but can't be sure. The question is, are these issues related?Hard to say, if they are related, as the retention of gears when selected is a gearbox issue, unless the clutch is not disengaging sufficiently to allow you to select it. Either way, its catch 22, replace the clutch and still have the gearbox issues and you have missed the perfect opportunity to service the gearbox. Yet replacing the box, may not cure your situation either. The cheapest option, initially, is the replacement of the thrust bearing, and see if the problem still exists.
Stella Artois said:
Hard to say, if they are related, as the retention of gears when selected is a gearbox issue, unless the clutch is not disengaging sufficiently to allow you to select it. Either way, its catch 22, replace the clutch and still have the gearbox issues and you have missed the perfect opportunity to service the gearbox. Yet replacing the box, may not cure your situation either. The cheapest option, initially, is the replacement of the thrust bearing, and see if the problem still exists.
Yes that makes sense, if the problem gets worse perhaps I could go all out and fit a replacement clutch & get a second hand gearbox for £300. BigMonk said:
Stella Artois said:
Hard to say, if they are related, as the retention of gears when selected is a gearbox issue, unless the clutch is not disengaging sufficiently to allow you to select it. Either way, its catch 22, replace the clutch and still have the gearbox issues and you have missed the perfect opportunity to service the gearbox. Yet replacing the box, may not cure your situation either. The cheapest option, initially, is the replacement of the thrust bearing, and see if the problem still exists.
Yes that makes sense, if the problem gets worse perhaps I could go all out and fit a replacement clutch & get a second hand gearbox for £300.
Good luck with getting a new clutch and replacement box for £300 !
daddysumo said:
BigMonk said:
Stella Artois said:
Hard to say, if they are related, as the retention of gears when selected is a gearbox issue, unless the clutch is not disengaging sufficiently to allow you to select it. Either way, its catch 22, replace the clutch and still have the gearbox issues and you have missed the perfect opportunity to service the gearbox. Yet replacing the box, may not cure your situation either. The cheapest option, initially, is the replacement of the thrust bearing, and see if the problem still exists.
Yes that makes sense, if the problem gets worse perhaps I could go all out and fit a replacement clutch & get a second hand gearbox for £300.
BigMonk said:
daddysumo said:
BigMonk said:
Stella Artois said:
Hard to say, if they are related, as the retention of gears when selected is a gearbox issue, unless the clutch is not disengaging sufficiently to allow you to select it. Either way, its catch 22, replace the clutch and still have the gearbox issues and you have missed the perfect opportunity to service the gearbox. Yet replacing the box, may not cure your situation either. The cheapest option, initially, is the replacement of the thrust bearing, and see if the problem still exists.
Yes that makes sense, if the problem gets worse perhaps I could go all out and fit a replacement clutch & get a second hand gearbox for £300.
Ah ok they are are hard to find apparently, then you need to get the ATB put in and I would suggest the bearing upgrade at the same time. Then either engine and box out or chassis side bar removal, lots of work either way unfortunately.
Steve
Good luck with getting a new clutch and replacement box for £300 !
I meant the gearbox for £300
im having the exact same problem with mine i noticed it today. and my mechanic has said the dame thing its likely to be the bearing. mine also does not make the noise when clutch is pressed down and does not always do ti when clutch it up but when put down and up again it starts. hopefull wont do to much damage and can wait to be sorted till november when car in garage for winter.
jdearden said:
im having the exact same problem with mine i noticed it today. and my mechanic has said the dame thing its likely to be the bearing. mine also does not make the noise when clutch is pressed down and does not always do ti when clutch it up but when put down and up again it starts. hopefull wont do to much damage and can wait to be sorted till november when car in garage for winter.
Please let me know how it plays out for you.Gassing Station | Noble | Top of Page | What's New | My Stuff