Disconnect the vacuum harness from the front axle shift motor.
Connect Vacuum Pump Tool J-23738 to the shift motor front port.
Apply 51 kPa (15 in) of vacuum to the shift motor and rotate the right front wheel to fully disengage the axle.
The shift motor should maintain vacuum applied to the front port for a minimum of 30 seconds. If the motor does not maintain vacuum, replace the motor. If the motor does maintain vacuum, proceed to the next step.
Disconnect the vacuum pump from the shift motor front port. Connect the pump to the shift motor rear port. Cap the transfer case connecting port and apply 51 kPa (15 in) of vacuum to the motor.
The shift motor should maintain vacuum applied to the rear port for a minimum of 30 seconds. If the shift motor does not maintain vacuum, proceed to the next step.
Remove the cap from the shift motor transfer case connecting port and check for vacuum at this port. If vacuum is not present, proceed to the next step.
Rotate the right front wheel as necessary to be sure the axle has shifted completely. The axle must be shifted completely in order to open the shift motor connecting port.
Check the vacuum at the shift motor transfer case connecting port
again. If vacuum is still not present, replace the shift motor. If vacuum is present at
the port, refer to the service diagnosis charts.
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