FORWARD TANDEM AXLE DIFFERENTIAL LOCKUP FAILS TO ENGAGE OR DISENGAGE

TM 9-2320-270-20-1

TROUBLESHOOTING - CONTINUED

MALFUNCTION

TEST OR INSPECTION

C O R R E C T I V E ACTION

55. FORWARD TANDEM AXLE DIFFERENTIAL LOCKUP FAILS TO ENGAGE OR DISENGAGE.

Start engine and build air pressure to operating level (TM 9-2320-270-10). Shut

Step 1.

down engine charge line (1) to lockup control valve (2) by having assistant

operate control (TM 9-2320-270-10). Using mild soap solution, check for air

leaks in line (page 4-1).

If line is leaking, replace (page 4-609).

Inspect lockup control valve (2) for damage (page 4-1).

Step 2.

If valve is damaged, notify direct support maintenance.

TA239713

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