Acts like brakes are locked up
Gotta give us more than that. Could be plenty of things. Park brake switch? Stuck valve? When, why, where, what were you doing, etc.
If you were up north I'd say to see which compartment, rear end, or planetary had frozen water in it but I doubt NC gets that cold. I believe the old 460s were all simple hydraulic brakes with a Micro brake lock switch in the brake line. What have you done to trouble shoot so far? Did the brakes work properly before this? If it is a straight stick? Did a wore out shift fork slip and stick it in two gears at once. Seen that on two different well worn skidders in the past.