Final answer:
When removing the differential and crown gear assembly from the carrier, the first step is to remove the bearing adjuster ring locks. This must be done before removing the bearing adjuster rings to ensure the mechanism is not damaged and the bearings are not dislodged prematurely.
Step-by-step explanation:
The correct first step when removing the differential and crown gear assembly from the carrier is d. Remove the bearing adjuster ring locks. The bearing adjuster ring locks must be removed before the bearing adjuster rings themselves can be safely and effectively taken off. This is to prevent any potential damage to the mechanism and ensure that the bearings are not prematurely dislodged. Marking the carrier leg and bearing cup is also an essential step, but it generally follows after the locks have been removed, just before the adjuster rings and bearings are handled.