4 Wheel Drive/SUVs: 99 Chevy S10 4x4 problem, steel bolts, gasket material

Question
My 4x4 will not disengage it  is auto  push button
And it is stuck in 4hi

Answer
Tami,
This problem can range from a faulty switch, bad ground, broken wire to a faulty component in the transfer case.

Without looking at the vehicle it's extremely hard to diagnose the actual problem.  This model has three different transfer cases available.  These are the one Speed Automatic, two Speed Selectable, and the two Speed Automatic.  It sounds like you have the two speed automatic.  This one  would have a low range along with 4hi.

The major component that can fail and cause this problem is the motor/encoder, as it controls the shifting of the transfer case.  You should purchase a repair manual for this vehicle.  It can give you much more information about the possible problem.  This way, you can trouble shoot the problem, and confirm the faulty part yourself.  You can purchase the manual at most auto parts stores.

If you have someone who can work on this, or wish to check it out yourself, here are some basic instructions for removing and replacing this component.

  1. Remove the transfer case shield. Refer to Shield Replacement.
  2. Remove the transfer case wiring harness connectors from the motor/encoder.
  3. Remove the bolts that secure the motor/encoder to the transfer case.

Installation Procedure

  1. Position the motor/encoder to the transfer case.
Notice: Refer to Fastener Notice in Service Precautions.
Important: Do not use steel bolts to secure the encoder/motor to the transfer case.
Any encoder/motor bolts that are worn or broken must be replaced with the correct G/M replacement bolts. A steel bolt will cause accelerated corrosion that will destroy the integrity of the magnesium case.
  2. Install the bolts securing the motor/encoder to the transfer case.
         o Tighten the motor/encoder bolts to 37 Nm (27 ft. lbs.) .
         o Remove all gasket material remaining from the motor/encoder.
         o Ensure the motor/encoder aligns properly with the transfer case interior shifting components.
         o Align the motor/encoder mating surface detent with the transfer case mating surface detent.
  3. Install the wiring harness connector to the motor/encoder.
  4. Install the transfer case shield. Refer to Shield Replacement

Carl