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Old 02-03-2025, 01:21 PM   #1
Masot
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Default Pressure Plate 9" diaphragm

Hi guys.

Do you know the model of pressure plate with diaphragm for 9" to adapt?

I looked at information on the forum and only saw 10" on rockauto

https://www.rockauto.com/en/catalog/...ure+plate,1988

Thanks
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Old 02-03-2025, 03:43 PM   #2
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Default Re: Pressure Plate 9" diaphragm

Go look at the Centerforce websight
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Old 02-03-2025, 04:05 PM   #3
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Default Re: Pressure Plate 9" diaphragm

Look at early mustangs
I have one in mine but can’t remember the model id was supposed to fit
Did a lot of looking to find it


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Old 02-04-2025, 04:56 PM   #4
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Default Re: Pressure Plate 9" diaphragm

Thanks.
I read that with a more powerful engine it is better to have a 10" clutch disc. I am going to install a diaphragm pressure disc and fit a 10" clutch disc for my Volvo five-speed gearbox.
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Old 02-04-2025, 07:56 PM   #5
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Default Re: Pressure Plate 9" diaphragm

The 10 inch diameter is a much better idea. You will be happy with that decision.
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Old 02-05-2025, 09:02 AM   #6
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Default Re: Pressure Plate 9" diaphragm

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Thanks Ronnie!
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Old 02-05-2025, 11:27 AM   #7
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Default Re: Pressure Plate 9" diaphragm

What transmission and throw-out bearing are you using? Many of the modern diaphragm clutch plates have fingers that do not "bend up" toward the tips. This is fine with a smaller diameter throw-out bearing (like we have on modern transmissions), but it can be an issue if you're using a 32 - 48 Ford transmission with the big-wide throw-out bearing.

What can happen is the throw-out bearing OD hits the diaphragm fingers in the "middle" of them - instead of on the ends/center when depressed. This is NOT how the clutch is supposed to work and can cause issues.

I recently had a well-known clutch manufacturer test their diaphragm pressure plates with the wide Ford bearing (as they were pushing me toward a diaphragm clutch).

After placing their clutch/disc in a test jig (using a 32 - 48 throw-out bearing) they came back to me and recommended that I NOT use their diaphragm pressure plates for this application.

I think they were a bit surprised when they actually tested their clutch setup. This caused them to switch me over to a Ford Long style pressure plate. They saw the issue I was mentioning when they actually tested their clutch setups with a wide bearing.

Just something to think about!
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Old 02-05-2025, 07:26 PM   #8
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Default Re: Pressure Plate 9" diaphragm

Thank You
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Old 02-06-2025, 11:49 AM   #9
Tim Ayers
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Default Re: Pressure Plate 9" diaphragm

Quote:
Originally Posted by Bored&Stroked View Post
What transmission and throw-out bearing are you using? Many of the modern diaphragm clutch plates have fingers that do not "bend up" toward the tips. This is fine with a smaller diameter throw-out bearing (like we have on modern transmissions), but it can be an issue if you're using a 32 - 48 Ford transmission with the big-wide throw-out bearing.

What can happen is the throw-out bearing OD hits the diaphragm fingers in the "middle" of them - instead of on the ends/center when depressed. This is NOT how the clutch is supposed to work and can cause issues.

I recently had a well-known clutch manufacturer test their diaphragm pressure plates with the wide Ford bearing (as they were pushing me toward a diaphragm clutch).

After placing their clutch/disc in a test jig (using a 32 - 48 throw-out bearing) they came back to me and recommended that I NOT use their diaphragm pressure plates for this application.

I think they were a bit surprised when they actually tested their clutch setup. This caused them to switch me over to a Ford Long style pressure plate. They saw the issue I was mentioning when they actually tested their clutch setups with a wide bearing.

Just something to think about!
Please tell us who this manufacturer was so we'll know for future reference.
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Old 02-07-2025, 10:41 AM   #10
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Default Re: Pressure Plate 9" diaphragm

Hey Tim: I had a couple custom steel flywheels and clutch plates/discs made by RAM (to my specifications). I wanted the billet flywheels to be light (24 lbs) -- so they are back-cut and scalloped (see the picture). The set below will finally get installed in my 32 Cab in the coming months.

We discussed the whole diaphragm issue and I had them check their clutch plates.

Some diaphragm manufacturers have fingers that are designed (the ends of them) to deal with this situation . . . but buying off of Rock Auto . . . may not be the best thing!

IMG_8371.jpg

IMG_8369.jpg
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