2003 Chevy Suburban 4WD does not disengage; 2003 Chev Subur

SUBURBAN003

MEMBER
2003 CHEVROLET SUBURBAN

Drive Train Axles Bearings problem
2003 Chevy Suburban V8 Four Wheel Drive Automatic

4WD fails to disengage on my 2003 Chevy Suburban k2500. When the 4WD switch is in "auto" mode and the engine is running, a continuous whistling sound emanates from under the right pasenger's side of the Suburban, aprox. mid way between the front and rear axles. Pressing the 2WD button does not do anything more then momentarily light up the diode indicator light beside it.

Had a garage mechanic plug in an OBII unit and the diagnostic indicated a 4WD fault, same message as displayed on the Suburban's display instrument cluster. The mechanics interpretation was that it could be a faulty actuator, or wiring to it, or both.

Where is the 4WD actuator located? What’s involved with overhauling it? Does the transfer case need to be drained before removing (if necessary) the 4WD actuator. Can you please inform me if photos “a” and “b” are that of the actuator:

and if photo “c” is the cable link that controls it?

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

First thing you must do is scan it with a tool that can read "B" and "C" codes regular variety scantools don't read anything but "P" codes. this will get you pointed in the right direction, here are your parts...