I have a 64 F100 with a 292. Three speed transmission. I have recently, 2 years and maybe 6K miles replaced the clutch. I was driving down the road and went to shift into high and the clutch pedal went to the floor. I pulled to the side of the road and was unable to get into gear with the engine running. I was able to get it into first with out the engine running. I started the truck while it was in gear, and rolled out. I was able to shift into second when the engine was turning at the correct speed, and in that way limped home.

I opened the cover and looked at the clutch and disk still has plenty of material, it is in effect brand new. The pressure plate is in good condition and holding the plate to the flywheel. There is however more distance between the fingers of the pressure plate and the release bearing than seem correct, about 1 to 1 1/2".

So, I called the local Brake Clutch and Driveshaft shop that sold them the parts and asked for their opinion. They said it must be a problem with the linkage. That makes sense, but I have checked the linkage from pedal to release lever and I can't find anything wrong. I adjusted the nut that presses against the lever to the end of the rod and still I am not getting enough movement on the release bearing to activate the fingers of the pressure plate. When I first made the adjustment it seemed to work, but then failed again.

I have examined the linkage and cannot see any bent or broken parts. This is not a precision mechanism. Any fault which suddenly leaves the linkage about an inch short should be obvious. But I can't find it.

Has anyone seen something like this before?

 

The long clutch release rod attaches to the clutch pedal, then routes thru the toe board to the clutch equalizer (Z) bar.

The rod has two 90 degree ends that use nylon bushings. The bushings disintegrate, the 90 degree ends begin to crack, eventually snap off. Not pleasant!

Clutch pedal then drops to the floor, lays there like a drunken sailor.

There were two different clutch release rods used on 1964 F100/250 2WD's. The serial number is the last 6 digits of the VIN

C1TZ-7521-B .. Clutch Release Rod, approx. 17 3/4" long / Obsolete ~ 2 available NOS

Applications: 1961/63 F100/250 2WD - 1964 F100/250 2WD before serial number 460,001.

C4TZ-7521-B .. Clutch Release Rod / Obsolete ~ No Ford dealer or obsolete parts vendor has any.

Applications: 1964 F100/250 2WD from serial number 460,001.

COAZ-7526-A .. Clutch Release Rod Nylon Bushing / Reproduced

Applications: 1961/77 F100/350 - 1966/77 Bronco - 1960/80 misc Ford/Merc Passenger Cars.

Parts catalog pic: Notice 7521 attaching to clutch pedal (7519), t'other end to equalizer (Z) bar (7528).

 

Thank you very much, but the clutch release rod is still intact and in place. When I move the pedal the entire linkage still operates. It just seems to be an inch short. But I will try to take a closer look at the upper end of the vertical release rod and where it attached to the pedal. That is up under the dash and not easy to see and not visible from the engine compartment.

 

The only reason the clutch release rod would drop to the floor...and stay there, is if the clutch release rod has broken.

 

I'm sorry, I must have given you the wrong impression, the clutch release rod did not drop to the floor. The pedal went to the floor, meaning that there was no resistance when I pressed on the clutch pedal. Because the linkage is still intact, while the spring 7523 is in place, the pedal returns to the normal position. When I step on the pedal the I feel the resistance of the 7523 spring, but not the resistance of the pressure plate.

 

There are two nuts on this rod, one much larger than the other. The larger nut (351062-S in parts catalog pic) has a rounded face that pushes against the clutch fork.

You have to loosen, then tighten both of these nuts to adjust the clutch.

How long is this rod? It's possible someone installed a rod from another vehicle that's too short, so when the clutch disc wears, you cannot adjust it properly.

 

Yes, I have from time to time adjusted the clutch just as you describe, and it continued to adjust until the disc was so badly worn that it was slipping. And I replaced the clutch with a new disc and a new pressure plate. And they have worked well until it failed suddenly.

So the length of this rod is not the problem. This is the mystery. It seems like it must be the linkage, but every part of the linkage is in good working order. I just took a close look at the top of the pedal where it pivots and at the connection of the clutch release rod. These look fine. The Z bar looks fine. The adjusting nuts and that rod look fine. The release lever is a very heavy piece of steel and it looks fine. The trunion looks fine, the release bearing collar and the release bearing look fine. The bearing is pressed onto the collar and spins freely.

None of the obvious failures of the linkage can be the problem. I have removed the pressure plate and it seems fine. The three fingers move, but only with serious pressure. The fingers are slightly compressed when the plate is bolted to the flywheel, but that is what keeps the disc in place and the transmission turning.

How much distance should there be between the fingers of the pressure plate and the release bearing when the there clutch pedal is all the way up? In my clutch it is about 1 1/2" or perhaps more. I know the release bearing should not be touching the pressure plate fingers, but I am not sure what is the normal space.

Also what should be the total movement at the end of the lower clutch release rod, where the adjusting nut is located? In normal operation how far does that piece move when the clutch pedal is depressed?

Thanks for your attention.

 

I have the parts catalog, but not the shop manual, so I have no way to answer your specific questions regarding measurements.

Grab ahold of the equalizer bar and see if it wiggles on the 2 pivots it rides on.

 

Do you mean the Z bar?

It has some play, it is not a precision fit, but less than 1/8". The brackets were replaced when one of the broke back in 08 or 09.

This seems to be within the normal range.

 

FoMoCo: Equalizer Bar, that some peeps call the Z bar.

 

if you could post a pic if would help

sounds like the rods are to short or bushing in z bar failed

 

The rod is not too short because it has worked all these years and just had a sudden failure a few weeks ago. The z bar is firmly attached at both ends. I replaced both brackets when one of them failed. In that case the z bar was just hanging there loose. It was easy to see the failure and I was able to get junk yard parts, because no one makes or sells those parts. I got them from Bob's F100 parts in California. The bar is still in place and it turns freely. But later I will check the brackets just to be sure. I will try to get some good pictures as well.

 

Make sure your bellhousing bolts have not worked loose. If you can no longer get the correct adjustment of the clutch, then something has bent or worn. Do you have the 4 bronze bushings installed for the z bar? Have a buddy help by pushing the clutch while you observe the operation of every component. The problem should become apparent quite easily.

 

That is what I thought. It should be quite apparent, but it is not. I have been over the entire thing myself and with a friend. Something should be bent, or broken or loose or worn out. Most like broken, because it was sudden and complete failure. I installed the bronze bushing in the zbar when I replaced the brackets. And the Zbar is not loose. I think will remove and check them after work today. It may be a waste of time, but it cannot hurt to remove and reinstall the zbar.

 

That you have not yet checked the z-bar tells me that you have not been as thorough as you might think. Check everything again. Look at each individual component and you will find it. Make no assumptions.