Clutch Adjustment on a 40

[philipswanson]

I adjusted my clutch on my 40 wagon so I had the 1" free play. Trouble is, now I don't have enough clutch action left. When the pedal is fully depressed, the first gear is still spinning and wanting to grind. What gives?

[Kube]

Usually this means there is wear in any number of contact points.
The clevis pins must all be at their nominal diameter : .312" if I recall correctly. The corresponding holes in the links must also be true and to their nominal diameter: just over .312".
The ball and socket (half "moon" bushings) of the linkage must be as new.
The clutch release shaft and bushings must not be worn.
The clutch arm itself must not be worn at the shaft or those bushings and possibly the shaft itself will need to be serviced.
And finally, the clutch pressure plate must have been properly rebuilt. Too often, so called "rebuilders" do not pay any attention to the height of the three fingers. This specification is quite critical.
Also, if the flywheel was ground too far, you will never achieve proper adjustment.

Rest assured that even though a clevis (example) is only worn "a little", those "littles" add up exponentially to create the situation you are experiencing.

[philipswanson]

Thanks Kube for all the great information. When I bought the car, there was enough clutch action but no free play. Sounds like I got a mess to fix here, especially if its the pressure plate fingers and/or flywheel.

[19Fordy]

"Kube" hit a home run.

[Mart]

You could reduce the "1 inch" as long as you are prepared to monitor it and always make sure it does not diminish to zero.

As Kube says, ensuring all the clevises and pins are in good order is a necessity, but also the pedal pivot and bushings.

Having a good pedal return spring is also important.

If I was dealing with a linkage that had a lot of wear in the pivots, I might look at attaching a return spring at the clutch lever to keep all the play at the one end, until I was able to tear it down and address the issue properly.

There may be some oil or other contamination on the clutch plate that would cause it to drag. You might try momentarily selecting second before selecting first when preparing to pull away from rest. this can help, but not if the clutch is not actually releasing.

You can do a test to see if the clutch is releasing properly. It may seem abusive, but isn't when done with skill and care.

Check my video, but please forgive the knackered throw out bearing.

https://youtu.be/PC_1gKwSrZE Not for the faint hearted.

Mart.

[drolston]

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I fooled myself on adjusting the clutch on my '41 by not pulling the pedal back up to a hard stop against the underside of the floorboard. I had put on new sponge rubber grommets that are supposed to seal the hole through the floor when your foot is off the pedal; the clutch grommet was hanging up against something and not letting the pedal return all the way. What I thought was 1" of free movement was really more like 2.5", which did not leave enough travel to fully disengage the clutch.

I trimmed the rubber grommet so it cleared everything and then readjusted. Works fine now.

Also, I will disagree just a little with Kube; the clutch mechanism is pretty tolerant of wear and slop, if and only if you have a good strong clutch return spring on the pedal, and a good throwout bearing return spring. The springs take up whatever slop there is in the linkage, so when you push, all the pieces are already in contact.

[supereal]

Shifting the transmission in my '47 developed a problem, which I thought was due to some adjustment failure. What I found was that a floor mat used to protect the rather expensive carpeting had shifted ahead just enough to prevent full clutch release. I am happy to have found this before I decided to tear into clutch linkage! Some times we overlook the obvious.

[philipswanson]

Originally Posted by drolston

I fooled myself on adjusting the clutch on my '41 by not pulling the pedal back up to a hard stop against the underside of the floorboard. I had put on new sponge rubber grommets that are supposed to seal the hole through the floor when your foot is off the pedal; the clutch grommet was hanging up against something and not letting the pedal return all the way. What I thought was 1" of free movement was really more like 2.5", which did not leave enough travel to fully disengage the clutch.

I trimmed the rubber grommet so it cleared everything and then readjusted. Works fine now.

Also, I will disagree just a little with Kube; the clutch mechanism is pretty tolerant of wear and slop, if and only if you have a good strong clutch return spring on the pedal, and a good throwout bearing return spring. The springs take up whatever slop there is in the linkage, so when you push, all the pieces are already in contact.

I think this is the same problem I have because I notice that the clutch pedal is not coming up nearly as far as the brake pedal. I recently replaced the snubbers (seals under the floorboard) on both pedals but for some reason the pedals are not equal when they come up. I would think they should be pretty much the same level when relaxed.

[drolston]

I think you found your problem. They should come up even with each other.

[philipswanson]

The reason the pedals are not coming up equally is the floorboard. The Carpenter bumpers I used are pretty thick and the one on the clutch pedal does not seal all the way up because it hits the steel frame around the wood floorboard first before the wood. This keeps it from coming up totally and making a good seal. It doesn't appear that anything can be done there except taking the seal back out and cutting it thinner. Also the clutch linkage is not worn and all pivots fine. No free play in the linkage at all but the clutch adjustment rod is pretty much totally screwed out in the direction of travel. Difficult to diagnose from here. It could be an issue with the pressure plate and/or flywheel. ????

[Krylon32]

I'm no clutch guru but isn't 1 inch of free play a lot? I've been telling my customers about 1/4 inch and monitor it so it stays that way. Am I cutting things to close?

[drolston]

Absent extreme wear or loose frame mount of the clutch release shaft, that threaded eye bolt should have enough threads to reach proper adjustment. The stock unit is 4" long; is that what you have?

A flywheel that has been shaved and a nearly worn our clutch disk could get you near the end of the adjustment threads. No way to check that without pulling the engine or transmission.

[19Fordy]

Krylon, The Ford manual says:.

"Clutch pedal free travel of 3/4 to 1 in. for the 1939 models and 1 to 1 1/4 in for 1940 models before the resistance of the springs is felt."

[philipswanson]

My clutch must be out. I adjusted the 4" rod all the way out to get maximum throw on the pedal and gears still grind. Won't even go into second or third with engine running. What's strange is last year when I drove it, it was fine. Now all of a sudden, no clutch action.

[philipswanson]

[QUOTE=philipswanson;1735597]My clutch must be out. I adjusted the 4" rod all the way out to get maximum throw on the pedal and gears still grind. Won't even go into second or third with engine running.

Maybe I am turning this adjustment the wrong way. Which way would give me more clutch and less free play? I definitely need more clutch. So should I lengthen or shorten the rod? Maybe I am going about this all wrong.

[19Fordy]

Turn clevis CW to increase or CCW to decrease the pedal travel, according to the Ford manual shown above.

[Mart]

lengthen.

[philipswanson]

I have it lengthened as far as I can but still not enough clutch to put it in any gear.

[B-O-B]

Krylon32:
I was always told/taught that 3/4"-1" for the clutch free play.

[Krylon32]

Thanks