pressure plate specifications

3

32phil

Well-known member
I need a little info.
I have an 8BA engine I want to use with a 39 Ford transmission.
The flywheel is drilled with 6 holes in 3 groups of 2 and it appears to be for a 9.5 to 10 inch clutch disc.
I have a new 10" clutch disc that fits the 39 transmission input shaft.
Can anyone help me with the proper pressure plate to use?
The holes in the flywheel have a 3''center to center spacing.
The pressure plate I have is 3 1/8'' spacing.
No one in my area is willing to drill the pressure plate.
Any ideas?
Thank You, Phil
 
3" is odd... the 3.125 is the correct spacing for ppbolts for 10" clutch pp, 11" is 3.375 I think. Usually if there are any dimensions off, the they are in the holes of the pressure plate when manufactured. Absolute sure of the flywheel application?
 
When checking the spacing remember that the pp bolts are shouldered bolts so take that into consideration. I usually measure outside of one to insde of other .
 
Generally, you use a '49-'51 Merc pressure plate In that application. I hear they are almost impossible to find except specialty places like Speedway Motors. When I did the '50 Merc in my '36, everything went together because I used the Merc flywheel and pressure plate and an early Ford disc. I think if you go Ford, the flywheel has to be redrilled. The later disc is 1" spline (I think) while the earlier one is 1 3/8".

I don't think I'd drill new mounting holes in a pressure plate either.
 
The spacing of 3.00” (center to center) indicates that the flywheel was drilled for the regular 9.5” pressure plate and clutch. This was the normal clutch for 1949-53 Ford passenger cars which are coupled with the transmission’s with the 1” x 10 spline input shaft.

Since you’re using a 1939 transmission (with the 1-3/8” input shaft) you cannot use the 9.5” clutch. The solution is to either have the existing flywheel redrilled to the bolt pattern of the 10” pressure plate, or purchase one of the new flywheels that is already drilled for this bolt pattern. We and other suppliers sell this flywheel. Then you can run the usual 10” clutch and pressure plate that was commonly used on 1942-48 Ford passenger cars or the same thing as used for the 1948-53 Ford pickup trucks.
 
I was able to buy a Borg and Beck [Merc style] pressure plate from my local rebuilder. He said that some fork lifts still use that style pressure plate. Check with your local rebuilder.
 
I have an 8ba in my '39 p/u. Used the 9 1/2" PP for the 8ba and the 9" disc for the '39 trans. Maybe not the correct way to do it but it's been working for over 5 years with no issues.
 
I'm running the same set up as 51504bat in my 32 pickup, done 15,000 miles with no problems. I know of 2 others running the same setup down under with no problems.
Phil.
 
Just a quick update
I purchased a Mercury flywheel, Borg & Beck pressure plate and 10" clutch disk from Irontrap Garage.
This apparently is the correct combo for what I'm trying to do. 50 Merc/39 Ford trans
Thank You to everyone for their replies
Phil
 
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