Clutch not disengaging properly?!

DRG-ler

DRG-ler

Senior Member
Hi everyone.


For about two or three years now, I've been having a problem where the clutch doesn't seem to be disengaging properly. I can't shift gears smoothly anymore. Every time I try to shift at a stoplight, it makes a loud noise, and people are giving me strange looks. It's just not fun to drive anymore.


I've put in fresh w600-oil, and the oil level is correct. The pedal isn't loose on the shaft. It has about two to three centimeters of play, so the clutch isn't slipping... Everything should be fine. But it just doesn't seem to be disengaging properly. As long as the transmission oil is still very cold, shifting is reasonably okay. Not great, but usable. But as soon as the engine and transmission warm up, shifting gets progressively worse. Sometimes I can stand still for one or two minutes with the clutch fully depressed, and the gears are still grinding very loudly!


What could be causing this, and how can I fix it?


Greetings from Berlin
Andy


Please excuse my poor grammar; I'm using a translator.
 
Well, the Model A transmission is notable for having to "double clutch." But that is passing between 1st and 2nd, and 2nd to 3rd. More notably 2 to 3.

Keep in mind that the 600W being sold by many vendors would be "thin" compared to the original darker lube of the era. I brought home some REAL 600W from the power plant and tried that - and got better but not great results.

My best success is to use STRAIGHT STP Oil additive. Yeah, I know. Its not a lubricant. But it pretends REAL WELL. And I'm not alone.

https://www.facebook.com/groups/MAFCA/posts/1645666282133621/

But, you say your issue is at a stoplight - which would be downshifting from 3 to 1, or 1 to 2?

Joe K
 
Andy-
Look for a crack on the clutch actuator arm on the side of the bell housing. It will prevent the clutch from fully disengaging in all gears.

Check idle RPM (not set too high).
 

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  • Cracked clutch release arm.jpg
    Cracked clutch release arm.jpg
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Hello, make sure the clutch arm isn’t cracked, usually the arm will develop a crack around where it is fastened to the adjustment arm causing the clutch not to fully release.
 
The problem occurs every time I engage or shift gears! I'm aware of the double-clutching due to the lack of synchronization and I do use it. Despite this, it still happens. Even when I try to shift from neutral! It also happens when shifting from 3rd to 2nd, or 2nd to 1st and vice versa, despite double-clutching!


I'm aware that different oils react differently. I use Rektol SAE 250, which has the same properties as the 600W version.


https://www.rektol-klassik.de/de/pr...-100---SAE-140---API-GL-1-163.html&no_boost=1


This oil was specifically developed for this purpose and has been successfully used by many Model A owners here in Germany. It's also the oil recommended by the German Model A Owners' Association.



https://www.ford-model-a-ig.de


@Jim, the lever is in perfect condition.
 
If all external linkage appears fine, you may want to remove the inspection cover on the flywheel housing to observe the clutch as you operate the pedal. You may find a pressure plate problem or other.
 
Lower the idle speed a bit and see if that helps. If the idle RPM's are too high, that makes shifting gears more difficult without grinding.
Marshall
 
You could try decreasing the free play at the clutch pedal. As long as the pedal has about one centimeter of easy movement before it gets harder to push, that is enough.

If the pilot bearing in the flywheel is locking up it would cause exactly the symptoms you describe. The input shaft of the transmission turns in the pilot bearing when the engine is running and the clutch is depressed.

The pressure plate adjusters could be not equal to each other. You can see them by taking off the inspection plate. When you push down the pedal to where it becomes hard to push, the throw out bearing should touch all the fingers at the same time.

Your clutch disc could have part of its friction material broken and bent up, or there could be a small foreign object stuck in it.
 
Besides the mechanical aspect of the situation, you should realize when down shifting the Model A 3-2 & 2-1 you will need to rev the engine much higher than you think to engage the lower gear. It takes a bit of practice.
 
What philosofriend says and in addition, could the clutch plate have been bent when the engine was installed. If the gearbox input shaft was not well aligned with the clutch plate as the engine slid into place. it could have been bent. That could leave one part of it remaining in contact with the flywheel even if the pedal is fully depressed.
 
Thank you all for your contributions. Unfortunately, I don't have much time to reply. Work is long and my free time is limited.


I can't lower the idle speed any further. It's already so low that the engine almost stalls. That shouldn't be the problem.


I'll take a look at the service opening and see if I can spot anything. Since this is a gradual defect that has gotten progressively worse, I suspect the pilot bearing is indeed the culprit. This is what other Model A owners with the same issue here in Germany have described to me.


A question about the pressure plate adjustment screws: What do they adjust?


I've noticed that while the clutch engages well and doesn't slip, the adjustment range at the pedal is at its maximum! My question is whether this indicates a worn clutch or an incorrect screw setting? What is the required friction material thickness for the clutch disc? Can this be seen/measured through the service opening?


Andy
 
I already answered that question in post #5... The lever on the outside of the pedal is fine! I haven't been able to check the clutch housing yet.


Andy
 
Check for the cracked arm first. It is the easiest to fix.
The fingers on the pressure plate are adjustable. They all need to be the same adjustment. You can use either 5/8 inch or 11/16 for your adjustment. If the fingers are not set equally, the throw out bearing will engage askew. This will eventually cause your pressure plate to fail. You can check the adjustment through the inspection hole on the clutch housing. Place a flat piece of steel over the back of the pressure plate and use a measuring caliper to measure from the bottom of the piece of steel to the finger to find the measurement.
 
DRG-ler said:
I already answered that question in post #5... The lever on the outside of the pedal is fine! I haven't been able to check the clutch housing yet.


Andy
Click to expand...


In case you did not know this:

Did you know that if you depress the clutch pedal and hold it down that the crack will remain open?

The original arms are forged steel and flexible.

When you release the pedal the clutch arm crack will closeup.

This is why you MUST be under car and looking at the arm at same time someone is pressing the pedal and holding the pedal down.

Otherwise the crack will close up and you will think that arm is fine.
 
Last edited:
A question about the pressure plate adjustment screws: What do they adjust?


They adjust the actuating fingers so that they are all at the same correct level so that the throwout bearing touches all of them at the same correct time.

Dick M's post describes how to check the adjustment of each of the 6 levers.
 
Having another person actuate the clutch while checking the arm for cracks, also have the person actuate the clutch and watch the pressure plate and release bearing assembly. Rotate the engine so you can observe all the way around the pressure plate as it actuates.

After checking everything visually, if all looks good, unfortunately there may be some disassembly required. One other thing, a long shot. Pull the top off the trany and inspect the gears and shafts for excessive play. Something has been slowly failing, or at least is out of tolerance.
 
We have the same problem with the gears grinding. Can't start the car in gear as it will jump. We have to run it in neutral. We can see the throw-out bearing pushing in on the fingers running. This all happened as the car was put in the garage and not started for about two months. It sounds like we have the same problem as DRG-ler. If he got his problem fixed it sure would be nice to know what he did. Thanks.
 
I had a similar problem on my open cab pickup The clutch was dragging even though I had a minimal amount of free play the pin was slowly shearing on the fork that pushes against the throw out bearing If that is the case with yours the only way to fix it is to remove the bell housing And repair the sheared pin which requires either removing the engine or transmission unfortunatly.
 
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