40 Transmission Problems:

40ford

40ford

Well-known member
The transmission in my stock 40 coupe is showing some problems.At times everything shifts good with no problems.At other times the shifting from first to second and third it feels real stiff and grinds sometimes!I don't understand how everything can work normal most of the time and then start showing these problems?Any ideas or experience with this problem?
 
Could be that your problem is in the clutch & pressure plate "system" and not actually a transmission problem. I have been on that "boat" before.
 
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40ford said:
The transmission in my stock 40 coupe is showing some problems.At times everything shifts good with no problems.At other times the shifting from first to second and third it feels real stiff and grinds sometimes!I don't understand how everything can work normal most of the time and then start showing these problems?Any ideas or experience with this problem?
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"First things first" as is often said...
Make darn certain the linkage is not worn and then, make certain it is properly adjusted.
My guess is the clevis bushings are worn. A worn transmission gear(s) won't tend to grind and then not grind. Once they fail, they have failed.

So, check the linkage (both ends) of both shifting rods. Check that the forks on the transmission cover plate are not worn. Then, check the linkage on the clutch shift arm as well as the clutch shaft / bushings in the transmission case. All of these items add up and will cause the issue you describe.
 
Thanks, gentlemen.I just could not understand why it shifts ok sometimes and other times it feels like something is binding somewhere!Could it possibly be something in the shifter side plate on the side.What I am trying to get at is hopefully I am not looking at a transmission pull.I know it has had a shifter bushing kit for the arms from DC installed.
 
40ford said:
Thanks, gentlemen.I just could not understand why it shifts ok sometimes and other times it feels like something is binding somewhere!Could it possibly be something in the shifter side plate on the side.What I am trying to get at is hopefully I am not looking at a transmission pull.I know it has had a shifter bushing kit for the arms from DC installed.
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From your description of the problem, it sounds as if something is worn. Most likely outside of the transmission.
You replaced the bushings... did you check the male ends for wear?

I'd suggest you disconnect the clutch arm pivot and see how worn the bushings and release shaft are worn.
I can;t stress enough the fact that even a little wear here and there adds up very quickly. Enough so to cause issues.
 
Thanks Kube.If say the shifting forks are worn out or other parts on the shifting side plate are these parts available?
 
Can the shift plate be removed from side of transmission with transmission still in car?I know very little about transmission and scared to death of them!I will have to take to mechanic and let him start I guess by removing the shift plate and possibly see what may be the problem.I checked the shift linkage and everything is good and snug with no play to be found.I noticed today sometimes when i try to shift to second it will not even go in like something is blocking it off.I don't even get it to grind!
 
If your going to have someone check it for you, you need to find someone familiar with old transmissions and especially Ford transmissions. You might list your location if you want some suggestions on where to go.
 
40ford said:
Can the shift plate be removed from side of transmission with transmission still in car?I know very little about transmission and scared to death of them!I will have to take to mechanic and let him start I guess by removing the shift plate and possibly see what may be the problem.I checked the shift linkage and everything is good and snug with no play to be found.I noticed today sometimes when i try to shift to second it will not even go in like something is blocking it off.I don't even get it to grind!
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Man, that sounds like the linkage is adjusted poorly. I am speaking about the two 'arms" at the top of the steering column. When the transmission is in neutral, those arms should be parallel to each other and level
at the "3 o'clock" position.
 
I checked my arms like you said Kube and they are perfectly lined up.Have you ever seen the detent balls and springs give some kind of problem like what I am having?I just can't believe this transmission is failing!Heck,it is the first one I have had in a 40 that does not jump out of second gear when you back off on the throttle!
 
Is it hard to shift when "cold", and gets better when warmed up? Or vice versa? Have you checked the oil level, and do you know what oil is in it?
 
The temperature does not seem to have anything to do with the problem.I first checked the oil level and it was very low and thought maybe this was the problem.Nothing changed after I brought the oil level up to where it should be.
 
40ford said:
I checked my arms like you said Kube and they are perfectly lined up.Have you ever seen the detent balls and springs give some kind of problem like what I am having?I just can't believe this transmission is failing!Heck,it is the first one I have had in a 40 that does not jump out of second gear when you back off on the throttle!
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I personally have never experienced a problem with the indents sticking. I suppose it can happen. Perhaps take the rods off the shifting arms and attempt to move the levers by hand. That will tell you quickly whether or not there's an issue there.
 
I am getting a little over 1/2 inch of clutch free travel.I have never really liked the clutch setting after everything was replaced including having the fly wheel resurfaced.The clutch pedal is just about at the top before you feel the "friction point".How do you adjust to help this?
 
40ford said:
The clutch pedal is just about at the top before you feel the "friction point".How do you adjust to help this?
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Look at the drawing below. Adjustment is made by making this rod / clevis assembly SHORTER. Clevis #7532, and rod #7521. Try adjusting a couple of threads' length at a time. Un-hook the #7523 SPRING first to make it easier to take the pin(s) out. DD

Flathead_Clutchassy_1940-48_85hp.jpg
 
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Seems like adjusting and making rod shorter could only make my problem worse as far a gear changing?
 
I just about agree with that statement.......IF the clutch is NOT fully disengaging. Your problem could still be resulting from a combination of four worn holes, and two worn pins, as KUBE suggested. That slight wear can add-up to quite a bit of movement at the pedal pad.

The reason I suggested the adjustment is because you said you only have about 1/2" of free play.......not enough. That would also be a symptom (very little free play) and a cause for the clutch not engaging until almost fully released, as you stated. You're going to have to do some careful investigating of your ACTUAL conditions. DD
 
Could it be a faulty pilot bearing keeping the input shaft spinning with the flywheel even when the clutch is engaged?
 
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