2004 S-10 push button 4x4 front drive won't completely disengage.

Marvin

• 85242 Answers
• Posted on Nov 08, 2008

SOURCE: 4x4 won't engage. light blinks all the time.

The light blinks to alert you that a problem exists in the control module for the 4X4, contact expert Toyota Ed he is the service manager of a Toyota dealer, he knows his stuff

SOURCE: 1991 Bronco wont go into 4 wheel high or low

sticky or broken lockout ,take apart and clean,inspect the center aluminum piece,if the center moves around alot then the lockout is broken,if not then regrease and try it again

Harvey N Tawatao

• 3854 Answers
• Posted on Jan 05, 2010

SOURCE: 98 4X4 4WD ENGAGES WHEN BUTTON IS PUSHED BUT IS

There is a vacuum switch on the top of the transfer case, driver side and when that fails, your front hub stay's locked in the on position. Your going to have to disconnect the three vacuum line harness from the switch in the transfer case and with a open end wrench, you can work the switch out and replace it with a new one and the cost is around $25.00 "Auto Zone / NAPA", Dealer $65.00. Good luck and keep me posted and hope that has gone bad. The other place that would cause this is the return spring in the front differential has gone bad and needs to be replaced and that, is a bit more work to replace but can be done with common tools. You can pick up all these parts at Auto Zone or Parts Source and they will have the step by step instructions for you to get the job done and the vacuum switch takes about 15 min to replace and if you can not sneak under the Blazer and have to jack it up. Be safe and add extra 15 min so will take you 30 min to replace.

Be safe and keep me posted.

Testimonial: "Changed vacuum switch but it didn't fix problem.Does that switch turn on the lights on the button on the dash ? Still have same problem."

SOURCE: i have a 99 silverado 4x4. the 4 wheel drive does

it probably need a mode selector switch.

SOURCE: 08 f150 4x4 on front

If I read this correctly ( which I might not have, bit early for me ), the front drive shaft will engage ( from the transfer case ) but the front wheels are not engaged ?

If so, sounds like either the vacuum from the IWE ( Integrated Wheel End ) is not being released, or the IWEs have had an issue with part vacuum ( damage vacuum lines ) and the IWE gear is rounded off.

If you pull the vacuum lines at the IWEs ( there are 2 lines, 1 is the vacuum line, the other is the vent tube that routes up into the engine compartment and is not attached to anything ), the front wheel should engage ( might need a 5 * turn to mesh the gears ). With the vacuum lines off, jack up the front axle ( take precautions, chock the rear wheels, parking brake, jack stands, etc ) see if the front wheels are engaged ( turning one wheel should turn the other ). The option is to do this after the truck has sat over night, and the vacuum has been released out of the vacuum reservoir.

If the wheels turn correctly ( engaged ) I would think the contact plates in the transfer case are not making contact. Good starting point for this is the connector on the side of the transfer case, some times this gets gummed up, and the pins do not make good contact. The contact plates in the transfer case are used for a few things, one of them is to signal the IWE solenoids to release vacuum to the IWEs.

Operationally vacuum holds the IWE ( Integrated Wheel Ends ) out, and once vacuum is removed the spring engages the IWE.

Here is a black diagram of the IWE vacuum system