Express 3/4 Ton Van V8-5.7L VIN R (1998)
8. On axles without a locking differential, remove the pinion shaft.
9. On axles with a locking differential, remove the shaft part way, and rotate the case until the pinion shaft touches the housing.
10. On axles with a locking differential, use a screwdriver or similar tool to enter the differential case and rotate the lock (1) until it aligns with the
thrust block (2).