I found this a couple years ago, hope it helps you.
Fixing a stuck transmission shift lever on a Ferguson or early MF tractor
Transmission main shaft lever hang-up is common on
most models of Ferguson/MF tractors after they get a little
wear on them. The shift lever is held down by a spring.
When you start to shift you will unconsciously lift up on
the lever. This causes the shift lever to go into the shift
fork on the other shift rail. That rail cannot be moved because
of the lock on the back of the transmission that prevents
it from going into two gears at the same time. Once
you have both shift rails in the neutral position you can
then move the shift lever.
If necessary, move the tractor to a level spot and turn off the
engine. If you have a high-low tranmission, put the high-low
shifter in neutral to relieve any pressure that might be on the
Remove the transmission filler plug. Using a light, look inside
and you will see a large gear. Depress the clutch.
If the transmission is stuck in reverse, take a long
screwdriver or a small pry bar and pry the large gear
forward. Pry it backward if it is stuck in first gear.
If it is stuck in second or third gear you can see the shifting
fork for them though the filler hole. Pry the fork forward if
hung in second and backward if stuck in third. If you happen
to go too far it will go in the other gear. You need to get it in
You should be able to feel the detent balls pop in the
grooves in the shift rail as you move the gear or fork.
Through the years I have probably unstuck at least a thousand of them this way.
To avoid this condition when changing gears, use the
open palm of your hand to push the lever into neutral.
Then grasp the lever to put it in the gear you want.
- Big Dean Austin