LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> Drivelines & Axles >> Differentials & Drive Axles >> Front Drive Axle - 4WD >> System Tests >> Test D: Automatic Four-Wheel Drive Does Not Disengage (A4WD)

Test D: Automatic Four-Wheel Drive Does Not Disengage (A4WD)

  1. If you were sent here from the symptom index table, go to next step. See SYMPTOM INDEX (BLAZER - JIMMY CANADIAN, SONOMA & S10 PICKUP)  table. If you were not sent here from the symptom index table, go to DIAGNOSTIC STARTING POINT .
  2. Start the engine. Inspect the instrument panel to see if the Service 4WD light is illuminated. If Service 4WD light stays illuminated with engine running, see appropriate TRANSFER CASES article in TRANSMISSION. If Service 4WD light does not stay on with engine running, go to next step.
  3. Inspect the vacuum hoses for kinks, plugged lines or damage. If damage to vacuum lines is found, go to next step. If damage is not found, go to step  5.
  4. Repair or replace the vacuum hoses as necessary. After repair, if front axle disengages, system is okay. If front axle does not disengage, go to next step.
  5. Disconnect the vacuum hose at the vacuum actuator. Inspect the vacuum actuator for movement. If vacuum actuator moves to disengage front axle, go to next step. If vacuum actuator does not move to disengage front axle, go to step  7.
  6. Replace the vacuum actuator solenoid valve. After repair, if front axle disengages, system is okay. If front axle does not disengage, go to step  8.
  7. Replace the vacuum actuator. See ACTUATOR ASSEMBLY  under REMOVAL & INSTALLATION. After repair, if front drive axle disengages, system is okay. If front drive axle does not disengage, go to next step.
  8. Inspect the clutch cable for damage or binding. If clutch cable is damaged or binding, go to next step. If clutch cable is not damaged or binding, go to step  10.
  9. Replace the clutch cable. See CLUTCH CABLE REPLACEMENT  under REMOVAL & INSTALLATION. After repair, if front axle disengages, system is okay. If front axle does not disengage, go to next step.
  10. Disconnect the clutch cable from the clutch fork. Inspect the operation of the clutch fork using Hub Engagement Tool (J-33798). If front axle disengages, system is okay. If front axle does not disengage, go to next step.
  11. Replace the clutch fork. See CLUTCH FORK REPLACEMENT  under REMOVAL & INSTALLATION. If front axle disengages, system is okay. If front axle does not disengage, go to next step.
  12. The cause of concern may be in the front drive axle. Disassemble the front drive axle. Inspect for damaged components. See DIFFERENTIAL CARRIER  under OVERHAUL.
scientia non olet · About LEMON Manuals