V8 clutch and pressure plate on Model A

[Seabees]

Howdy boys, I don't know when or why I did it, but I have a V8 clutch and pressure plate in my '28 coupe. Can't remember when I put it in? Yeah, getting forgetful. The clutch doesn't have more than around 500 miles on it, and I notice it is starting to slip. So, out came the trans, removed the PP and clutch, and it looks fine. Little wear on the clutch, but nothing out of the ordinary. So, why is it slipping? I have an inch free play at the pedal, however I noticed one of the 3 fingers on the PP is out of adjustment with the other two. This of course would not affect the slipping I am feeling, but it will need to be addressed. My question is, would any of you know what the spring pressure at a given length should be? I can measure it, but I don't know what the parameters are. There are 6 springs in the PP. Thanks, surely one of you experts out there will have the answer!

[redmodelt]

You might also try asking on the Early V8 section.

[Marshall V. Daut]

I experienced two NEW V-8 clutches slipping badly immediately after installation in two separate engines 15 years ago, finger adjustment notwithstanding. REAL fun to change and not inexpensive. I don't know if there was a run of bad V-8 clutches dumped on us stupid Americans from overseas back then or whether the old Daut luck kicked in again I ended up with the only two bad clutches out of a production run of 1000. 'Dunno. I just know that I have been leery of using V-8 pressure plates ever since. 'Sounds as though at least one of those clutches found its way into "Seebee's" Model A.
Did anyone else have the same experience a few years ago?
Marshall

[johnneilson]

A couple questions;
how much HP is the motor making? it is a matter of torque.
does the PP have the "flyweights?
How thick is the clutch disk?

John

[Synchro909]

The V8 clutch in my brother in law's car doesn't slip but he can't stop it shuddering. I'm wondering whether these two issues might be related. I don't want to hijack this thread but it seems reasonable that they are related.
Comments?

[Seabees]

Sponsored Links (Register now to hide all advertisements)

To answer a couple questions, the engine has a 5.5 head along with a counterweighted crank. Stock carb, with electronic ignition. Nothing too fancy. The PP does have flyweights, so it's the correct one. The finger that is out of adjustment shouldn't have an effect on holding the clutch to the flywheel, so that is why I'd like to test the springs. Still haven't found an answer to that question. I haven't noticed it "Shuddering". I was going up a fairly steep hill in 3rd gear (not lugging the engine) when I noticed the slippage.

[Seabees]

And yes, I posted this on the V8 page. Thanks for the help guys!

[Kurt in NJ]

From the ford repair book
At 1-9/16 color brown spring 147-153 lbs
Then put a pin in one of the holes in the pressure plate itself and measure the thickness
Originally 1.246 — if more than .020 less the springs need shims, if the springs are shimmed the yokes that bolt to the cover need shims

[johnneilson]

Ok, the flyweights add clamping force to the clutch
The springs do have a direct impact on the clamping too
I have had some with very stiff springs and driving in traffic is unbearable
So now the question is how thick is the disk?
If less than .280 it will probably slip
John
Btw I have seen the tractor pp used and these are spring force only
They will slip with moderate coaxing

[Seabees]

Thanks Kurt, the springs in this plate are pink or red. Which "Ford Repair Book" did you get the info from?

[Kurt in NJ]

there may be other springs used later, but the specifications should be the same, the thickness of the insulating washers is not addressed

[Seabees]

Great, thanks Kurt! I just ordered the book! Thanks again!

[katy]

My 1939-48 Ford shop manual lists the following for spring length, also at 1&9/16", Pink 150-160 lbs, Red 125-130 lbs. They list 9 different spring colours, including "none". Lots of info on reassembly and release lever adjustment.

[Seabees]

Well boys, I found the adjustment for the PP fingers, and they are within spec. I haven't tested the springs yet, but I really don't think that's the problem. I checked the adjustment with a new clutch. The PP is in good condition, looks like a new one. The machine marks aren't even worn off yet, so I really don't think that is it. The old clutch looks good enough to use too, but since I have a new one, I put it in. Damn, I hate to put it back together without knowing, but I don't know what else to check. I had an inch of pedal free play before I took it apart, so I don't think the throw out was dragging, causing the clutch to slip. No binding in the clutch release shaft, and the spring returns as it should. Unless I hear some good advise, I reckon I'll assemble things and let you know if it works. Thanks for the help, I hate it when things like this pop up, but I always seem to learn something new.

[updraught]

Are the clutch plate springs hitting the flywheel bolts?
https://www.fordbarn.com/forum/showthread.php?t=179423

[Seabees]

Nope.

[Seabees]

Howdy boys, ok here's the latest. I tested the springs, and at 1-9/16" compression, I should have 150-160 psi. I only have 140 at best. If I compress the spring entirely, I have 147. So that tells me the springs are weak, or, the wrong ones are installed. I have looked all over the world and can't find anyone who rebuilds PP's. No where! A lot of them have gone out of business, with no one taking over. All I need is a source for new springs. I'd really like to talk to some who knows the PP's so I can make an informed decision on how to proceed. Why is this so difficult? Surely there are others out there with V8 PP's. Damn it!

[katy]

Have you tried Detroit Clutch Masters?

[Seabees]

katy, do you have a phone number?

[katy]

Try 1 586-759-1300
https://www.mapquest.com/us/michigan...ters-462757966

There/s also: https://fortwayneclutch.com/