Push [POWER OFF]. Set the main circuit breaker to the OFF position.

Lock the main circuit breaker. Use an approved lock with an approved safety tag. Close the primary air valve.

Remove all the electrical [1] and pneumatic [2] connections from the gearbox assembly. Put marks to record their locations. Put labels on all cables and hoses.

Record the wiring configuration for the spindle motor [3]. Disconnect the wires. Remove the tool release piston (TRP) [4]. If the machine has through-spindle coolant (TSC), disconnect the necessary plumbing.

If the gearbox has a mid belt shield [1], remove it.

Make sure no cables are connected to the gearbox. Remove the gearbox from the machine.

Remove (5) of the (6) bolts from the gearbox assembly. Do not remove (1) of the bolts near the rear of the machine. Loosen this (1) remaining bolt. With your hands, pull the gearbox toward the spindle. This loosens the tension on the spindle belt [3]. Connect the hoist to the gearbox [2]. Lift the hoist until it supports the gearbox. Remove the (1) remaining bolt from the gearbox assembly. Slowly lift the gearbox.

Remove the gearbox from the machine. Move the transmission oil pump assembly [4] and the spindle encoder [5] to the new gearbox.

Connect the high-gear air hose [1] from the CALM cabinet to the fitting on top of the air-over-oil assembly.

Connect the low-gear hose [2] to the fitting on the top plate of the gearbox labeled LOW.

If you have a 35-psi air regulator [3] on the input of the shift solenoid in the CALM cabinet, you must remove it. Replace the 35-psi air regulator [4] with the tee fitting [5].

If you have an adjustable air regulator on the input of the shift solenoid, set the air regulator to 80 psi.