Chevrolet Repair: chevy suburban, chevy suburban, test light

Question
QUESTION: hey i have a 95 chevy suburban with a 350 in it. i go to use my four wheel drive and i can lock it in on the floor and it feels like it puts the transfer case in to low or high depending if i go up or down but the front wheels aren't spinning what could be my issue i have already checked fuses so what do you suggest next

ANSWER: Hey Shane,

  Look underneath and see if the shaft from the transfer case to front differential is turning.  If it is then there is an electrically actuated gas filled actuation lever mounted on the front differential.  When voltage is applied to it the gas expands and moves the lever inside the differential.  Its a weird setup but works efficiently.  It could be the voltage supplied to the differential actuator or the actuator itself.


Wayne Howie


---------- FOLLOW-UP ----------

QUESTION: so how hard is it to fix the actuator and or get to it

Answer
Hey,

  The actuator can not be repaired and if it is defective it needs to be replaced with a new or used one. It is mounted on the differential with two 13mm headed bolts to my recollection. Make sure there is voltage to the actuator on the light blue wire.  the black wire should be a ground.  If you put a test light (clip side on black and point side on light blue) it should light up when the 4wd is actuated.  IF you have no power there it could be the transfer case switch that is mounted on the transfer case. They get stuck sometimes and the ball does not release due to lack of use.  They can be removed, lubricated and reused in some cases.  The transfer case switch has three wires to it.  The brown wire is 12v in the Key on position, the light blue is the feed to the actuator on the diff and the grey with black tracer goes to the PCM to let the PCM know its in 4wd.


Wayne Howie

a new actuator is 289.00 Canadian
a new transfer case switch is 34.22 Canadian



Make sure you check all your fuses!!!!!


Wayne