The footplates where rot and planks of wood replaced them, hey under a plank there was a diff lock pedal. I have since replaced the footplates and freed the pedal and now she turns. I have been able to do a couple of road runs and the final drive whines and coasting down a hill feels it is holding the tractor back and on the flat slight inclines kill the speed. I know it is not the brakes as I can rock each wheel a bit on the play/dwell of the diff.
I have jacked up the rear wheels one at a time and turned them by hand with a lot of resistance, one wheel in the air and the other on the floor so to me just turning the diff. Should it be so tight?
The oil is beige colour probably 50yrs old I was looking to change it but not sure it would be that simple as nothing has been simple so far.
Has the old farmer who is 95 now busted the final drive by running on constant diff lock?
Any help would be gratefully received.
All the best and Happy Christmas from Brighton by the sea. (Sea air rots tractors

Ian