4 Wheel Drive 1997 Suburban4 wheel drive

GRW

MEMBER
1997 CHEVROLET SUBURBAN
V8
AUTOMATIC
126,000 MILES

My 4 wheel drive is not working. When you engage the 4 wheel drive switch on the dash there is an audible clunk but the lights flash in both lo &hi 4 wheel drive. I drove it and it does not feel like it is engaged. Is it most likely the actuator? I unplugged the electrical connection and there seems to be no change in symptoms.

Tuesday, January 25th, 2011 AT 6:46 PM

3 Replies

HMAC300

MECHANIC
48,601 POSTS

There is an actuator on the t-case and another on the axle. You'll have to check each one to see whichone is or isn't working.

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Tuesday, January 25th, 2011 AT 8:54 PM

GRW

MEMBER
3 POSTS

Can you fill or hear the actuators as the work. The actuator located in the front of the vehicle ( axle) I removed and had my son change place the vehicle in neutral and shifted between 2 wheel and 4 wheel low and hi. There was no result. I checked the current on the 4 prong plug. It is receiving 12 volt thru 1 prong. 1 is a ground. There was no change in current when the vehicle was once again shifted. The same prong continued to have 12 volts. No other prongs had voltage. Any ideas?

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Tuesday, January 25th, 2011 AT 9:12 PM

HMAC300

MECHANIC
48,601 POSTS

As I dont know if you have electronic shift or not i'm sending 2 harnes schematics. According to the schematic there are only two wires to teh actuator on front axle but that's a schematic and isn't reality. Alot of times the actuators get corrosion in them and won't work. The can be sdisassemlbled carefully and cleaned out andthey will work again. They haveto be sealed with silicone on the edgesvery carefully however. You may have a badmodule as well.

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