Dodge ram truck 3500 1996 Service Manual page 89

B R
DIFFERENTIAL AND DRIWEL1NE '3 - 23
D I A G N O S I S AND T E S T I N G (Continued)
DISCONNECT AXLE/SHIFT
MOTOR
DIAGNOSIS (CONT'D)
F O U R - W H E E L D R I V E O P E R A T I O N D I A G N O S I S
FOUR-WHEEL DRIVE INDICATOR
LIGHT DOES NOT LIGHT WHEN
TRANSFER CASE SELECTOR IN
4H OR4L POSITION.
RAISE VEHICLE SO ALL FOUR
WHEELS ARE FREE TO ROTATE.
START ENGINE, DEPRESS BRAKE PEDAL.
PLACE TRANSFER CASE SELECTOR IN 4H
POSITION AND TRANSMISSION LEVER IN
DRIVE (AUTOMATIC) OR IN FIRST GEAR
(MANUAL) TO CONFIRM TRANSFER CASE
ENGAGEMENT IN 4H. LET WHEELS
ROTATE SLOWLY.
FRONT DRIVE
SHAFT DOES
NOT ROTATE.
FRONT DRIVE
SHAFT TURNS.
INSPECT TRANSFER
CASE LINKAGE.
CHECK TRANSFER
CASE. REPAIR AS
NECESSARY.
FRONT AXLE
CONNECTS.
FOUR-WHEEL DRIVE
INDICATOR LIGHT
DOES NOT LIGHT.
INSPECT FWD INDICATOR
SWITCH, WIRING, AND
LAMP FOR DAMAGE.
REPAIR AS NECESSARY.
RECOMMENDATION:
CHECK VACUUM
SHIFT SYSTEM
FOR PROPER
OPERATION.
PLACE TRANSMISSION
LEVER IN NEUTRAL
POSITION.
FRONT AXLE
DOES NOT
CONNECT.
REMOVE VACUUM HOSES
FROM AXLE SHIFT
MOTOR PORTS.
START ENGINE. TEST FOR VACUUM
AT HOSE REMOVED FROM OUT­
BOARD PORT O N SHIFT MOTOR,
SHOULD BE BETWEEN 10-20 IN HG.
NO VACUUM
OR LOW VACUUM.
STOP ENGINE
K
VACUUM OK
INSPECT INTAKE MANIFOLD
VACUUM SUPPLY HOSE CONNECTION,
TRANSFER CASE VACUUM SWITCH
CONNECTION, VACUUM RESERVOIR, AND SHIFT
SYSTEM VACUUM HOSES FOR PROPER CONNECTION,
RESTRICTION, LEAKS, AND DAMAGE.
REPAIR OR REPLACE AS NECESSARY.
CONNECT A VACUUM PUMP
TO THE OUTBOARD
SHIFT MOTOR PORT.
APPLY 15 INCHES HG. VACUUM
AND ROTATE LEFT WHEEL.
NO VACUUM
FRONT AXLE
CONNECTED.
CHECK TRANSFER CASE
VACUUM SWITCH. REPLACE
OR REPAIR IF SWITCH
PLUNGER IS DIFFICULT TO
MOVE OR BINDS.
FRONT AXLE
DOES NOT
CONNECT.
INSPECT VACUUM HOSES
FOR LEAKS, KINKS, ETC.
REPAIR AS NECESSARY.
REMOVE SHIFT MOTOR
HOUSING COVER. CONNECT
VACUUM PUMP TO
SHIFT MOTOR PORT.
REPLACE SHIFT MOTOR
IF ARMATURE DOES
NOT MOVE IN AND OUT
FREELY.
REMOVE SHIFT MOTOR HOUSING
COVER. INSPECT SHIFT FORK,
COLLAR, AND AXLE SHAFTS.
REPAIR OR REPLACE AS
NECESSARY.
_ _ _ i : .
REMOVE SHIFT MOTOR HOUSING
COVER. INSPECT SHIFT FORK,
COLLAR, AND AXLE SHAFTS.
REPAIR OR REPLACE AS
NECESSARY.
FRONT AXLE
WILL NOT CONNECT.
REMOVE SHIFT MOTOR HOUSING
COVER. INSPECT SHIFT FORK,
COLLAR, AND AXLE SHAFTS.
REPAIR OR REPLACE AS
NECESSARY.
FRONT AXLE
WILL NOT CONNECT.
REMOVE SHIFT MOTOR HOUSING
COVER. INSPECT SHIFT FORK,
COLLAR, AND AXLE SHAFTS.
REPAIR OR REPLACE AS
NECESSARY.
J9002-96