Diaphragm Clutch

[belvedere666]

Has anyone used a diaphragm style clutch to replace their old lever style?  Do you have a part number?I know there is one out there somewhere because I had one on an old P20 engine. My friend has it in their car now but I can’t find any real details to buy another one. I think it’s a 10” vs my stock 9 1/4, and my flywheel has two bolt patterns. Stock clutch cover fits the smaller pattern.

looks like there’s a part number in this old picture, but it’s hard to make out.

[bones44]

I put one in my D5 back in the middle "60" and ran it until I parked the car for over forty years. When I redid the car in 2014 it was replaced with another diaphragm clutch from Rock Auto. If my memory severs me correctly it was for a 60 or 61 chevy 6 cylinder.

[FarmerJon]

On 1/26/2022 at 12:18 PM, belvedere666 said:

Has anyone used a diaphragm style clutch to replace their old lever style?  Do you have a part number?I know there is one out there somewhere because I had one on an old P20 engine. My friend has it in their car now but I can’t find any real details to buy another one. I think it’s a 10” vs my stock 9 1/4, and my flywheel has two bolt patterns. Stock clutch cover fits the smaller pattern.

looks like there’s a part number in this old picture, but it’s hard to make out.

Did you ever figure out what clutch this was? 

Do you notice a big difference going from the lever style to the diagram type?

 

[Scott in ct]

DC truck parts  in Washington state, sells a 10” 10 spline diaphragm clutch disc and plate. Maybe it will fit your car. They are good to deal with. I tried to post a link but no good. Scott.

[belvedere666]

22 minutes ago, Scott in ct said:

DC truck parts  in Washington state, sells a 10” 10 spline diaphragm clutch disc and plate. Maybe it will fit your car. They are good to deal with. I tried to post a link but no good. Scott.

I used one from a 60s Plymouth Belvedere. It seemed to work ok. Works with a standard size clutch disc. I’m  using an A833 trans with OD, which requires a 23 spline disc.

I had the diaphragm pressure plate in for a little hole and removed it. I was having some problems with the trans install. I only went back to the stock lever style because I needed to narrow down some issues. I had too many changes going on at once. You’re supposed to remove the over center spring, and adjust the clutch accordingly.

I still have the diaphragm style in my garage and I’ll swap it back in if I ever have to remove that transmission again. That thing is heavy.

[FarmerJon]

I am building a r10 Od, so will need a 10 spline disk. Looks like 61-62 and 65-69 C10 pickups with 6 cylinders have a 10", 10 spline clutch. I have to work of finding more info and cross references, but if they will work, there will be cheap and mild performance options...

 

I know that the pedal pressure is reduced,but are the diaphragm pressure plates physically lighter than the lever type?

Edited February 24 by FarmerJon

[Scott in ct]

The over all weight is about the same, at least not noticeable by hand to me. Here is a picture of mine, Dodge , that I bought from DC truck parts. Scott.

[FarmerJon]

21 minutes ago, Scott in ct said:

The over all weight is about the same, at least not noticeable by hand to me. Here is a picture of mine, Dodge , that I bought from DC truck parts. Scott.

If you dont mind, what is the part number on the clutch disk?

 

[Scott in ct]

No numbers, just the makers mark, Scott.

[FarmerJon]

Scott, I assume you installed this clutch in your truck?

I am having trouble installing it on my passenger car bellhousing. The pressure plate will fit with no clutch disk installed,  but with the disk in place the PP hits the clutch fork windows, and cannot be lined up. Anyone else had this issue?

[Loren]

Diaphragm pressure plates usually require a different Throw Out Bearing. The T.O. Bearing needs to have a rounded contact surface so the spring fingers can roll over it. The fingers ( for want of knowing a better word ) on the standard pressure plate slide across the flat T.O. Bearing. So that is an item of concern if you're making the switch.

Diaphragm Pressure plates have a low pedal pressure until they get worn, then it goes up. If you're familiar with this you can tell when a car needs a clutch just by stepping on the pedal.

Plymouth made a lot of Taxi Cabs and one of the mods in the Taxi package was a 10 inch clutch. Thus they drilled all the flywheels with two patterns of bolt holes. However if you're planning to replace a worn 9 inch with a new 10 inch clutch you need to know the 10 inch uses bigger bolts. They are 3/8 x 16 nc which seems to be just like Big Block Chevy ( forgive my foul language ) I just ordered some from Summit Racing $9.99. ( back ordered at this time )

The 10 inch original type clutch that I got came from AB. I told them I had a 49 Plymouth and I wanted a 10 inch clutch, no problem.

When you go to install your new clutch, you have to run a tap in the 3/8ths holes as they will have lots of crud in the threads. Start the tap on the clutch side as there is a straight section ( without threads ) which will align the tap and prevent cross threading. Rockauto has SKF T.O. Bearings which I hope are better than the noisy Chinese ones the AB sells. ( assume the Chinese bearings will last as long as the American made ones. I just can't put up with the noise )

 

[Scott in ct]

I installed the clutch in a powerwagon. I used a stock NOS throw out bearing. The original clutch was a 10" finger type. I went with the diaphragm for the lower pedal pressure. Good luck sorting it out, Scott.

[FarmerJon]

The truck bells must have a touch more space in em or have the clutch fork windows laid out differently.

I was able to use my die grinder and a burr to cut the clearance I needed to install everything. 

I forgot to take a victory picture with the transmission in.

I used ARP SBC pressure plate bolts (3/8-16, 1" under head length) part number 130-2201. They were almost perfectly flush with the back of the flywheel when installed.

Yes, my flywheel was already drilled for the 10" pattern. Very convenient.

Looking at factory American (Chevy) diaphragm clutch set ups, i see flat throwout bearings getting used. I wont stress about it, especially since the trans is already in. I used a nos "Green" USA made bearing that i cleaned and repacked.

I will get all the linkages (and OD wiring harness) installed tomorrow. 

Edited November 18 by FarmerJon