Diaphragm Spring

November 30, 2011

Can anyone explain simply to a non-mechanic how the diaphragm spring works, and whether it is attributable to premature clutch wear please?

Has anyone had problems with clutch after very few miles with Toyota, and been refused a warranty claim.

November 30, 2011

Hi Sandra,if you google diaphragm clutches, you will get lots of info on both types better than i can explain them to you.it gives the pro and cons of both.

good luck.

November 30, 2011

It's basically the bit that pushes the clutch friction plate against the flywheel when you let go of the clutch, and is the resistance you're pushing against when you push the clutch in to disengage it.

It also provides the clamping force on the clutch plate so if it's worn, then it won't clamp properly and you may get some clutch slip.

However, it will only get worn that bad if the driver is always holding down the clutch pedal when waiting instead of going to neutral; If your clutch problem is down to this, it deffo won't be covered by warranty as this'd be classed as driver error.

If you're just asking what a diaphragm spring is, it's basically ring with some springy 'fingers' arranged in a circle like this:

If you look carefully, you'll see that the 'fingers' curve up in the middle; That is where the clutch release bearing sits and is what pushes against the springy fingers when you push in the clutch pedal.

A good overview of how it works:

http://auto.howstuffworks.com/clutch.htm

My replaced one was flattened on one side which was causing the friction plate to only engage on one side instead of full-on and is why it felt like the clutch was slipping (It felt like the biting point was waaaay near the top, but once fully engaged I could floor it in 1st gear and get no slip! Weird symptoms so wasn't sure if it actually needed changing, but in the end I got it changed because trying to move off up a hill was getting really tricky!)

The friction plate for that particular clutch was worn smooth on the outside of the friction ring but virtually untouched on the inner bits due to it engaging at an angle instead of flat on.

Problem is you can't check without taking the clutch apart and that's a pretty big job; The labour charges alone would make it prohibitive to 'have a quick look' unless you or a mate have enough experience and don't mind doing it yourselves...!

December 1, 2011

It's basically the bit that pushes the clutch friction plate against the flywheel when you let go of the clutch, and is the resistance you're pushing against when you push the clutch in to disengage it.
It also provides the clamping force on the clutch plate so if it's worn, then it won't clamp properly and you may get some clutch slip.
However, it will only get worn that bad if the driver is always holding down the clutch pedal when waiting instead of going to neutral; If your clutch problem is down to this, it deffo won't be covered by warranty as this'd be classed as driver error.
If you're just asking what a diaphragm spring is, it's basically ring with some springy 'fingers' arranged in a circle like this:
If you look carefully, you'll see that the 'fingers' curve up in the middle; That is where the clutch release bearing sits and is what pushes against the springy fingers when you push in the clutch pedal.
A good overview of how it works:
http://auto.howstuffworks.com/clutch.htm
My replaced one was flattened on one side which was causing the friction plate to only engage on one side instead of full-on and is why it felt like the clutch was slipping (It felt like the biting point was waaaay near the top, but once fully engaged I could floor it in 1st gear and get no slip! Weird symptoms so wasn't sure if it actually needed changing, but in the end I got it changed because trying to move off up a hill was getting really tricky!)
The friction plate for that particular clutch was worn smooth on the outside of the friction ring but virtually untouched on the inner bits due to it engaging at an angle instead of flat on.
Problem is you can't check without taking the clutch apart and that's a pretty big job; The labour charges alone would make it prohibitive to 'have a quick look' unless you or a mate have enough experience and don't mind doing it yourselves...!

Used to work at a Ford dealership back in the Sixties and we were paid bonus on each job,Ford and BMC had a time for

almost all servicing and repairs.Things were a lot easier with the rear wheel drive when changing things like clutches.The best time we managed to change a clutch on a Mk 1 Cortina was 1/2 an hour.No chance of getting anywhere near that these days with modern cars.

Been told,that on some model of vauxhall you can replace the drive plate without removing gearbox.How does that work.

December 1, 2011

Hi

Thanks for your response.

Could the eco system contibute to/cause the problem of excess wear?

Clutch has to be depressed before you can turn on the ignition.

I do not believe the problem is caused ententirely by driver error.

='Cyker' timestamp='1322693797' post='1166951']

It's basically the bit that pushes the clutch friction plate against the flywheel when you let go of the clutch, and is the resistance you're pushing against when you push the clutch in to disengage it.

It also provides the clamping force on the clutch plate so if it's worn, then it won't clamp properly and you may get some clutch slip.

However, it will only get worn that bad if the driver is always holding down the clutch pedal when waiting instead of going to neutral; If your clutch problem is down to this, it deffo won't be covered by warranty as this'd be classed as driver error.

If you're just asking what a diaphragm spring is, it's basically ring with some springy 'fingers' arranged in a circle like this:

If you look carefully, you'll see that the 'fingers' curve up in the middle; That is where the clutch release bearing sits and is what pushes against the springy fingers when you push in the clutch pedal.

A good overview of how it works:

http://auto.howstuffworks.com/clutch.htm

My replaced one was flattened on one side which was causing the friction plate to only engage on one side instead of full-on and is why it felt like the clutch was slipping (It felt like the biting point was waaaay near the top, but once fully engaged I could floor it in 1st gear and get no slip! Weird symptoms so wasn't sure if it actually needed changing, but in the end I got it changed because trying to move off up a hill was getting really tricky!)

The friction plate for that particular clutch was worn smooth on the outside of the friction ring but virtually untouched on the inner bits due to it engaging at an angle instead of flat on.

Problem is you can't check without taking the clutch apart and that's a pretty big job; The labour charges alone would make it prohibitive to 'have a quick look' unless you or a mate have enough experience and don't mind doing it yourselves...!

December 1, 2011

Used to work at a Ford dealership back in the Sixties and we were paid bonus on each job,Ford and BMC had a time for
almost all servicing and repairs.Things were a lot easier with the rear wheel drive when changing things like clutches.The best time we managed to change a clutch on a Mk 1 Cortina was 1/2 an hour.No chance of getting anywhere near that these days with modern cars.

Yeah, so I've heard! Had a mate with an ancient Escort and it cost him £70 to get his clutch done! It was so old it was a cable clutch instead of hydraulic like the ones we have now! :lol:

It's much harder in the tiny FWD cars like the Yaris and Aygo (Barely enough space for the engine in these things! :lol: )

@piggy - If you mean the start-stop function, I don't know.

I wouldn't have thought so since you shouldn't be disengaging/engaging the clutch any more than normal - The only difference is the engine stops - but I've not had much experience with them :(