Preliminary Inspection

Before performing service, inspect transfer case oil level, transfer case mounts for wear or looseness, and gearshift control lever for distortion or excessive wear.

Inspect vehicle for aftermarket devices which could affect operation of system. Inspect system components for damage or defects which could cause symptom. Inspect all related ground points. Inspect related circuits for intermittent conditions and poor connections. Repair as necessary.

If no problem is found, determine if symptom is electronic or mechanical. If symptom is electronic in nature, see ELECTRONIC SYMPTOM INDEX  table under SYMPTOM DIAGNOSIS. If symptom is mechanical in nature, see MECHANICAL SYMPTOM INDEX  table under SYMPTOM DIAGNOSIS.