EMPLOYEE WAS PERFORMING MAINTENANCE WORK ON A BUCYRUS ERIE COAL SHOVEL AT THE TIME OF THE ACCIDENT. AFTER REPLACING A SEAL IN THE RIGHT HAND SWINGER, HE WAS ATTEMPTING TO REPLACE A PINION ON THE SHAFT OF THE SWING MOTOR. WHILE USING A FORKLIFT TO APPLY CONSTANT PRESSURE EE'S THUMB WAS SMASHED BETWEEN THE PINION AND A BOLT HEAD. EE MUST WEAR A THUMB SPLINT FOR TWO WEEKS.