Tru-Lok Differential
DIAGNOSIS AND TESTINGUNLOCKED
1. Block tires opposite the axle to be tested to prevent the vehicle from rolling.
2. Place transfer case in 4WD Low and automatic transmission in Park (1st gear if manual transmission).
3. Raise both wheels of the axle to be tested off the ground.
4. Turn ignition to the ON position and dash switch to the OFF position.
5. Rotate one tire by hand. The other tire should spin in the opposite direction.
NOTE: If wheel cannot be rotated the differential must be repaired/replaced.
LOCKED
1. Block tires opposite the axle to be tested to prevent the vehicle from rolling.
2. Place transfer case in 4WD Low and automatic transmission in Park (1st gear if manual transmission).
3. Raise both wheels of the axle to be tested off the ground.
4. Turn ignition to the ON position and dash switch to the ON position.
5. Try to rotate one tire by hand. You should not be able to rotate the tire.
NOTE: If wheel does rotate verify locker pump operation. If the pump is operating properly the differential must be repaired/replaced
TRU-LOK INDICATOR SWITCH
1. Turn ignition switch off.
2. Disconnect indicator switch harness (Fig. 44) from the differential housing.
3. Measure electrical continuity across the switch terminals. Circuit should be closed (zero resistance).
NOTE: If circuit is not closed remove differential and replace locker indicator switch.
TRU-LOK PUMPS
1. Connect a pressure gauge to the front pump.
2. Place transfer case in 4WD Low and automatic transmission in Park (1st gear if manual transmission).
3. Turn ignition to the ON position and push the dash switch twice to activate the front pump.
NOTE: If pump is not running, verify pump has (Fig. 45) 12 volts and a ground.
4. With the pump running the pressure gauge should show 5 psi.
NOTE: If pump does not produce 5 psi. replace the pump.