Cant get clutch to disengage after replacing clutch

[Rpanno]

Also posted this on The HAMB but I'm trying to cast a wide net here!

Hi all,

I'm hoping someone here has an idea or has come across this before.

Car: 1931 Ford roadster pick up
Engine: 1940 Flathead
Transmission: 1939 case

My dad and I recently pulled the engine to perform a laundry list of projects which included: rebuilding transmission with original LZ gears, change brake/clutch pedal shaft and bushings, new gaskets and grease on leaky F1 steering and finally change the worn out clutch since when we had the flatty out we saw just how abused it was. Throwout bearing and retainer spring were also replaced. All parts came from Mac Van Pelt (he is great resource and person btw!)

Long story short, we got everything back together car started up. I can shift through the gears just fine with the engine off but am not getting a fully disengaged clutch when the engine is running. After talking with Mac, he said a surefire way to identify clutch as not fully disengaged is to step on clutch pedal for 20 seconds while engine is running and if still unable to get into 1st or reverse clutch is not releasing completely.

I have '32 pedals to what looks like a Tardel '32 repop clutch release lever. I currently have the pedal linkage to 1" freeplay at the pedal and now the top of my clutch release lever is hitting the bell housing which is maxing out the TO bearing travel towards the PP. The clutch release arm is 5.5" long from end to end and I can't seem to find where else to gain more travel.

Any ideas would be greatly appreciated, I'd love to be back on the road soon since north Texas is finally getting some decent roadster weather plus there's a few shows coming up soon!

Thanks, Ryan

[Karl Wolf]

Use of roll pins (Hollow springs) to install t/o bearing arm to shaft, either inside or outside the bell housing. -Would account for excessive t/o arm travel. (Use bolts or solid pins)

...T/O Fork backwards??

I have the same set up, the pin that holds the arm to the shaft is almost horizontal, as you look at it, it's tilted slightly to the left, about 5 degrees... (I say that this way because my release arm is a forgery)
Other than that, my set up is all stock parts, fairly new.

Clutch disc backward; would account for lack of release...

Try starting in gear with foot on the clutch, pointed some where safe.

Karl

[Rpanno]

Originally Posted by Karl Wolf

Use of roll pins to install t/o bearing arm to shaft, either inside or outside the bell housing. -Would account for excessive t/o arm travel. ...T/O Fork backwards??

I have the same set up, the pin that holds the arm to the shaft is almost horizontal, as you look at it, it's tilted slightly to the left, about 5 degrees... (I say that this way because my release arm is a forgery)
Other than that, my set up is all stock parts, fairly new.

Clutch disc backward; would account for lack of release...

Karl

My first thought after extensive online "research" was that I boneheadedly installed the clutch disk backwards. I can see just enough though the inspection port that the collar on the clutch disk protrudes to the rear/pressure plate side which from everything I have seen is the correct orientation.

[41LjH]

I had a similar problem on my project. Turned out the t-out bearing as hitting the pressure plate levers because it was too big.

[Mart]

As yours is a non standard application, are you getting the required travel on the clutch pedal?

Does the clutch release if you adjust the free play out? In other words is it just on the point of releasing, but doesn't quite go.

A recent thread stated the length of the 32 release lever at 4-3/4" (or thereabouts) Do you think that is the active working length of your lever? (centre to centre, not overall length)

If you are sure the plate is in right, you need to test to see if the clutch will release.

Here's an idea - do you have anti-chatter rods in? Is the motor moving forward hence losing some of the travel of the release lever?

Would it work if you shortened the release lever a bit?

Mart.

[JWL]

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Did it work correctly before the disc change? If so, is the new disc thinner than the old one? This would change the position of operation of the arm and put it nearer the housing. Is the TO bearing and hub the same length as the old parts? Again, this would change the zone of operation.

Can you see the disc shock springs exposed inside the pressure plate when looking through the inspection window? I am thinking about a reversed disc here.

Is it possible the pilot bearing is driving the input shaft?

[Rpanno]

Originally Posted by Mart

As yours is a non standard application, are you getting the required travel on the clutch pedal?

Does the clutch release if you adjust the free play out? In other words is it just on the point of releasing, but doesn't quite go.

A recent thread stated the length of the 32 release lever at 4-3/4" (or thereabouts) Do you think that is the active working length of your lever? (centre to centre, not overall length)

If you are sure the plate is in right, you need to test to see if the clutch will release.

Here's an idea - do you have anti-chatter rods in? Is the motor moving forward hence losing some of the travel of the release lever?

Would it work if you shortened the release lever a bit?

Mart.

My pedal travel and therefore freeplay is currently maxed out by virtue of the top of the release arm hitting the bell housing. I'm maxed out on adjustment.

I don't have anti chatter rods in, I guess it's possible the engine is jumping forward just slightly enough to keep the clutch from fully disengaging?!?

It may work with a revised release lever but I find it odd that it worked before with this rod.

Originally Posted by JWL

Did it work correctly before the disc change? If so, is the new disc thinner than the old one? This would change the position of operation of the arm and put it nearer the housing. Is the TO bearing and hub the same length as the old parts? Again, this would change the zone of operation.

Can you see the disc shock springs exposed inside the pressure plate when looking through the inspection window? I am thinking about a reversed disc here.

Is it possible the pilot bearing is driving the input shaft?

Yes, it worked before the disc change and the new disc is considerably thicker than the old one. I'm using the same hub and the new to bearing appeared to be identical to the old beside not being completely shot!

I can see the disc shock springs from the inspection cover but you can see those on both sides of the disc. The clutch disc shoulder is facing the rear of the car in other words towards the pressure plate. I thought that is the correct orientation.

[40cpe]

I remember reading in the past of replacement discs being thicker than Ford specs. Since the disc came from Van Pelt, I would think he is aware and sells the correct thickness.

[1931 flamingo]

Did you also replace the pressure plate and were the fingers adjusted correctly??
Paul in CT

[Zeke...PA]

Did you by chance replace the cross shaft in the bellhousing ?

[Rpanno]

Originally Posted by 1931 flamingo

Did you also replace the pressure plate and were the fingers adjusted correctly??
Paul in CT

I did not change the pressure plate which at this point is starting to give me some grief that I didn't replace it. I made no adjustments to the pressure plate. My plate did not have the 3 bolts on the fingers like some I have seen pics of.

Originally Posted by Zeke...PA

Did you by chance replace the cross shaft in the bellhousing ?

No, but now that I have to pull it all out again, I will replace the cross shaft.

I'm just hoping that once I do these things it solves the problem

[V8COOPMAN]

Not sure I understand how replacing the cross shaft will help in solving your problem. DD

[Rpanno]

Originally Posted by V8COOPMAN

Not sure I understand how replacing the cross shaft will help in solving your problem. DD

Im not either but if I pull the engine/tranny again I really don't want to leave it to chance to see what is causing the problem.

I know Mac closes shop on the weekend but I'm waiting for an answer on the thickness of his clutches.

[Mac VP]

Had a chance to pop into the shop this afternoon and measured a fresh 9" clutch disc. We went thru this exercise before but I never recorded the measurement. It was 0.375" thick. For the record, I had also measured a stock Ford disc and it was virtually the same thickness.

The pressure plate might be at issue in his application....not sure but it's not one of ours so I can't address the potential problem either that.

If his clutch release shaft is original (and not modified by anyone previously) changing that will not change anything here, hopefully the release fork is not installed backwards.

I suspect the problem is in the clutch arm (7511 on the diagrams). It may have just been close enough with the worn disc to get it released, but the thickness of the new disc is more than the current geometry can move the linkage. A shortened arm would increase the throw distance of the clutch pedal.

[FortyNiner]

Sorry, still sounds like the clutch plate is in backward to me.

[CT AV8]

I think the diagram MacVP is referring to is the one I posted on the HAMB for a down under RHD application. In any event, before you start pulling the engine out I would suggest fabbing up an new arm from some 7/8" id tubing and flat bar following those dimensions. You could drill out a series of holes for the clevis on the bar and simulate different lengths. The shorter the arm, the more travel you will have. Easier than pulling everything out.

[Rpanno]

Originally Posted by CT AV8

I think the diagram MacVP is referring to is the one I posted on the HAMB for a down under RHD application. In any event, before you start pulling the engine out I would suggest fabbing up an new arm from some 7/8" id tubing and flat bar following those dimensions. You could drill out a series of holes for the clevis on the bar and simulate different lengths. The shorter the arm, the more travel you will have. Easier than pulling everything out.

I can tell you for certain that there isn't anywhere close to 2-3/8 offset in my clutch release arm from the pedal fork adjustment to the release shaft. I'm not the builder of my car, I'm the 2nd owner who gets to "enhance" all of the other guys work.

Between Mac's response and yours it would make sense that the arm isn't providing enough throw and that the previous set up work because the clutch disk was so worn that it didn't take nearly the amount of throw travel that the new clutch disk requires.

At least the prospect of not pulling the entire engine sounds better to me!

[CT AV8]

Yeah, the 2 3/8" offset may be wrong for your application and you would have to follow what you have. It can vary based on pedal placement. Anyway, it's the length of the arm and the 30 degree rotation for the pin that are relevant in getting maximum travel. Can you weld or know somebody with a welder? It's an easy job.

[Mart]

Just something to think about if you are contemplating shortening the effective length of the lever - Is the clutch pretty light to release at the moment?? If it is light, you could tolerate it being a bit heavier when you shorten the lever. If it is heavy, it will be heavier still when the arm gets shortened.

Mart.

[Karl Wolf]

My avatar is a 1930 frame, 59ab engine, "39" trans case, 1932 crossmember and pedals. I made a forgery arm to go on the clutch release shaft which absolutely needed the 2 3/8" offset... So that the clutch pedal to arm rod would operate in a straight line... ( I have seen people try to do this by bending the rod)

Anyhow, if there's something that you would like me to measure, feel free to ask.

Karl