11" clutch with a 3 speed?

GB SISSON

GB SISSON

Well-known member
The 59ab that I am overhauling in the evenings was from a tonner truck so it's flywheel is drilled for an 11" clutch. I have a new nos 11" clutch here and was wondering if this would work/fit in a 1/2 ton pickup with a top loader 3 speed in it. All my many flathead powered ford trucks have been big trucks. I have never driven, owned or worked on a 1/2 ton. If it does indeed fit, what are the pros and cons of using it? To go to a 10" clutch I have to get the flywheel to a machine shop the mainland for redrilling an then buy a new clutch and pressure plate. Then go back to the mainland to pick it up. I think I could re-drill it here. Does anybody do this on their drill press? Thanks in advance.
 
I would n,t use the 11in clutch, if you are care full you can refill it on the drill press,but a mill is more accurate,its an easy job on one,
Lawrie
 
Lawrie said:
I would n,t use the 11in clutch, if you are care full you can refill it on the drill press,but a mill is more accurate,its an easy job on one,
Lawrie
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So maybe the small automotive machine shop I have used on the mainland could do it while I wait. That would help matters. 11" clutch too stiff in the springs and or too heavy in general? I pretty much expected this answer, and I trust the experience here.
 
I rebuilt my 59AB and used the original flywheel and a new clutch, which just happened to be an 11". Wish I would have taken the time and redrilled for a 10". When I stop at a red light, i put it neutral and let the pedal out. To heavy for my little leg to hold it in that long. Stop and go traffic is even worse. This is in my 27 roadster with a 39 top loader 3 speed. Just my 2 cents.
 
Yes, I have the 10 in in my 33 and I would say its lighter than the 9in one on the pedal.
Lawrie
 
The machine shop is in the back of a long time family owned auto parts store. I think I will call them and have them get a clutch package ordered for me and they will have it in their hands when they do the job. I'll save my 11" setup for my tonner pickup that I plan to 'restore' after this pickup turned woodie wagon is finished. One less thing to buy for that one. Thanks.
 
I make a bushing the size of the crankshaft flange. This allows me to bolt 2 flywheels together (fords) This way tou can transfer the holes from a 9 or 10 inch bolt pattern to the 11 in flywheel. Have done this on may wheels.
 
Ol' Ron said:
I make a bushing the size of the crankshaft flange. This allows me to bolt 2 flywheels together (fords) This way tou can transfer the holes from a 9 or 10 inch bolt pattern to the 11 in flywheel. Have done this on may wheels.
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Thanks Ron, that's a good method but I don't have one drilled for 10" to transfer from, or else I would use it on this engine. I have 3 flywheels drilled for 11". I do have a used pressure plate for a 10" to get the pattern, but sure wouldn't want to be off center by much.
 
I have a 40 tudor sedan with an 11 inch clutch and a 39 transmission.The only down side is you have to drop the oil pan to change the clutch. Other wise everything works just fine.
The clutch parts were available at the local clutch rebuilder.
 
GB SISSON said:
The 59ab that I am overhauling in the evenings was from a tonner truck so it's flywheel is drilled for an 11" clutch. I have a new nos 11" clutch here and was wondering if this would work/fit in a 1/2 ton pickup with a top loader 3 speed in it. All my many flathead powered ford trucks have been big trucks. I have never driven, owned or worked on a 1/2 ton. If it does indeed fit, what are the pros and cons of using it? To go to a 10" clutch I have to get the flywheel to a machine shop the mainland for redrilling an then buy a new clutch and pressure plate. Then go back to the mainland to pick it up. I think I could re-drill it here. Does anybody do this on their drill press? Thanks in advance.
Click to expand...

I changed from an 11" PP to a 10" on the tonner. In addition to redrilling the flywheel I had it and the PP balanced as a unit and the flywheel refaced in the process. Just food for thought while everything is apart.
 
G.B. "springs too stiff" Then I'm totally missing something. The smallest trucks
we have are F6's which should have a 11" The largest are F8' and F800 & F900's that
likely have 12" or 13". Not one of these feel any different than my 46 car and my
old legs ain't what they use to be either. All I can think of is maybe we are dealing
with a super heavy duty pressure plate OR maybe clutch linkage could be different
from light to heavy duty. ???
 
This help?
 

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My 1945 1/2 ton pickup came stock with a non-sychro 3 speed and an 11" clutch. I replaced the ****** with another 3 speed and used the original 11" flywheel and pressure plate and put in a new disc.

I must be a lot stronger in the legs than I thought as I don't have an issue with the clutch.
 
When I said 'springs too stiff?' I was asking the forum if that may be the reason not to use it. I currently have 3 fh v8 trucks with the 11" clutch and have owned well over a dozen over the years. I just haven't owned a car or half ton as a comparison.
 
Terry said:
This help?
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So the threads for 9" are 1/4", and 10" are 5/16"? Also the holes in all my flywheels are drilled in straight without threads for the first 1/4" or so. I assume this puts the shear action onto the full sized shank of the bolt and not where there are threads. Are the correct bolts shouldered or just not full thread?
 
The Borg & Beck clutches use 3/8" bolts. Fords usually use the 5/16. I have no idea on the 337 truck & Lincoln but they may also be 3/8".

On clutches, the springs are not the only tension. The Long types have those flyweights to deal with. My Pop's old 52 F3 had the 11-inch with the old non-synchro 4-speed and it was only heavy if you had some RPM in there. It is a big heavy dam thing though. It makes for slow rpm build of the flywheel mass due to the extra weight. They are fine for low rpm heavy duty use and stump pulling.
 
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Well, since I'm not gonna be pulling stumps with the woodie, and we are going to the mainland on Sunday for my granddaughter's birthday, I think I'll drop the flywheel off behind the machine shop and have them order me a 10" clutch. Once again, now I'll have one for the tonner pickup. OK.... Just got off the phone with the machine shop and they don't like redrilling flywheels.... Maybe I can find one drilled for 10" off a stuck engine or someone with parts. I'll be traveling from Anacortes Wa to West Seattle on Sunday morning and back early that evening. Got an extra?
 
The issues with clutch/pressure plate size has to do with a lot more than spring tension. It involves the mass of the whole assembly and the distance of that mass from the centerline of the drive train. As rotorwench has already pointed out it also involves the pressure plate style. All of this slows down the rate at which the rotating mass can change. This is a good thing for a heavy vehicle/truck and not so good for day to day driving in a lighter vehicle/car.
 
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