Transmission or clutch problem

[fordnuttoo]

I have a '51 V8 Ford that will not go in low or reverse gear after the engine is warmed up. It will shift with no problems until the engine is warm. The clutch and pressure plate are new, the pilot bushing is new, throw out bearing is new, the flywheel has been resurfaced. What are we missing? Need help.
Thanks, Fordnuttoo

 

[flathead4rd]

Does it grind when trying to shift into first or reverse or does it just not physically go into either gear?

 

[rotorwrench]

Low & reverse are the same gear in there plus they are unsynchronized. If there is a problem with the cluster, the gear, or the shafting, it will give you trouble. Most of the old transmissions I open up have combinations of these problems in the low/reverse gearing due to forced shifting on the unsynchronized gear over its life span. There can also be problems with the shifting forks & linkages that can give problematic shifting symptoms.

Kerby

 

[Charlie ny]

ford nutto,
Could your problem be something as basic as the trans
lube coming up to temp and not providing the viscous drag that it did
when cold. Trans lube once at operating temp is pretty close to kerosene
in its fluid characteristics. As mentioned there is no syncro in 1st or rev
so you should be at a stand still prior to selecting these gears.
Charlie ny

 

[fordnuttoo]

It grinds when you try to pull it in to low gear, even at a full stop. If you go to 2nd gear and then to 1st it will go. I understand that this syncronizes the gears. The trans oil is new, as is all the other I stated. When cold, it shifts fine, no problem. The problem starts after it gets good and warm.

 

[Mart]

If the clutch releases properly there should be no grinding as such, but you will be aware of the unsynchronised gears engaging.

If the clutch is not releasing fully, then yes, they will grind, can't really say it should be worse when hot though.

Try this:

With everything warmed up, select 2nd and then 1st immediately.
Then select neutral and engage the clutch.
Then release the clutch, and with the pedal held down, select 2nd, and then neutral and count to 5 and then first. see i8f it grinds worse than selecting immediately.

Then try with a 10 second and 15 second delay.

The object is to try and tell if the clutch is dragging.

Here's the old school way to tell if your clutch is releasing..

(copied from a recent thread)


Ok, here's the scoop on how to test if your clutch is releasing properly.

With the engine running, without pressing on the clutch, slowly and carefully move the shifter towards reverse until the gears can just be heard to make the slightest contact - do not attempt to engage the gear. Hold the shifter so that the grating can be heard. Press the clutch pedal down and stop when the grating stops (the clutch has released). Then press the pedal all the way down, making a judgement on the relative distance between clutch release and when the clutch pedal stops moving.

This procedure should tell you if:
1, The clutch releases cleanly and there is plenty of movement after release (the ideal situation).
2, The clutch does release but the pedal is on the floor (time to make an adjustment or check lever lengths and ratios if a non stock linkage).
3, The pedal is on the floor and the clutch still has not released.

If you have situation number 3, then either there is something wrong with lever lengths etc ( in a non stock situation) or the clutch linkage is adjusted incorrectly, or the clutch pressure plate has theoretically released the clutch disk, but it has not released due to sticking due to contamination or warpage or some other reason.


Mart.