The common problem is a bad vacuum line to the actuator for the front axle. The actuator is under the battery. Not a great place for it if the battery ever leaks.
You can find the vacuum line where it comes out from under the battery tray, then follow it up to the solenoid. Then from there up to the intake. Look for cracks holes or damage. (I usually just replace them, they get crappy over time) Put a vacuum gauge on the hose and make sure you have vacuum when you select 4X4. If you have vacuum before the solenoid check after it. Then remove the battery and tray and check the actuator itself, they can tear, have acid holes or the clips to the cable can fail.
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Friday, December 18th, 2009 AT 1:29 AM