51 3 Speed Clutch Not Releasing?

H

hulleywoodworking

Member
1951 Ford F1, 239 flathead V8, 3 speed light duty remote shift transmission. Engine and transmission completely rebuilt. Newly rebuilt clutch, pressure plate, and throwout bearing from Fort Wayne Clutch.

I recently posted a question about the correct assembly of the synchronizer assembly, which was answered by Mac Van Pelt. I had pulled the transmission to remove and fix the synchronizer. Got it all back together and installed. Started the truck with the drive shaft still disconnected and ran through the gears.

So finally, my question. When the transmission is in neutral, the output shaft spins. I can stop it with my hands, but it takes a fair amount of pressure to stop it. When I push in the clutch pedal, the out put shaft completely stops. I have the clutch pedal free play adjusted to 1-1/8".

So what's going on here? Something's not right, I just don't know what.
 
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It sounds like your clutch is working ok.
If the engine is off, the clutch pedal is out and the trani is in neutral, can you easily turn the output shaft?
You should have no trouble turning it with two fingers, you should feel a little bit of the weight of metal you are spinning. If it is hard to turn, your trouble is in the transmission.
Terry
 
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Overkill-F1 said:
It sounds like your clutch is working ok.
If the engine is off, the clutch pedal is out and the trani is in neutral, can you easily turn the output shaft?
You should have no trouble turning it with two fingers, you should feel a little bit of the weight of metal you are spinning. If it is hard to turn, your trouble is in the transmission.
Terry
Click to expand...

It turns easily under these conditions.
 
Most likely the cause is the brass synchronizer rings making slight contact to the main drive gear. If you can Easily stop it by hand you have no issues and it should wear in just fine. This is very common especially on fresh rebuilt transmissions.
 
I think what you are experiencing is a real world example of how synchronizers in a transmission function.
 
Gear oil friction. The pilot shaft is turning engine speed. He cluster gear is being spun by the pilot gear , the top front gear. The top front gear, input or pilot gear, is dragging second gear around by oil friction against the synchro ring. Plus the same is happening with third gear synchro ring. The cluster gear is being turned by the pilot gear. The spinning cluster gear is submerged in gear oil which is dragging against the first and second gears also.
That may be some of the reason a lot of cars and trucks use ATF in there manual gearboxes.
Mercedes has used ATF in their four speed manual gearboxes for over 60 years.
I put gear oil in my five speed Aerostar. And had a nasty time shifting it. I did know it took ATF like my Volvo five speed and most other cars we service at work.
When you run a car on the lift in neutral, stick or automatic, one or both rear wheels will star to spin if you don’t apply the emergency brake. Oil friction.
 
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