Need help with stuck tranny

[AussieinNC]

We all know the correct way is to remove the trans and tear down and rebuild....however...

Pull the drain plug from the trans and let whatever goop is on the trans to seep out. Replace the plug,

Pour some diesel into the trans enough to cover the bottom gears, no higher.

Jack up the rear wheels and spin the tail shaft with the trans in neutral to circulate the diesel....let it soak for a few hours

Drain the diesel out and let it drip out overnight. Add some light engine oil again just enough to cover the lower gears and turn the tail shaft to circulate.

Drain and refill with gear oil to the full level plug.

You should be able to move the gear sliders back and forth now.

While you are at it, check the clutch plate is free of the flywheel and pressure plate surfaces...if its stuck, do yourself a huge favor and pukk the trans and fix is correctly.