Automotive Forums

I have a 2005 GMC Sierra Z71 in which I have had problems since I drove it off of the lot with the push button 4WD. The warranty is now out on it and I need to try and find the solution. I read online that it was more than likely the actuator on the front passenger side since the GMC part was notorious for being repaired. I purchased a new aftermarket one off line and I changed it out hoping to fix the problem. Well, as my luck goes. Nope! When I start the truck and the system goes through the routine lights on the dash display after that all of the lights on the push button panel go out. Is there some sort of sensor that was maybe triggered and either needs reset or changed out that I can take care of. It is sad to have a new vehicle that is 4wd and that has never been driven off road and abused. I appreciate your help in advance.  

Here is what I have found out so far. I did some reading online and found out that I am not the only one with this problem. The first item to look at is the actuator GM Part#26060073 for $60.00 plus shipping on Ebay located on the front passenger side differential. The OEM part is a bad design and it is recommended to use an aftermarket part. I replaced this part and I still had the same problem with the lights on the dash and not being able to engage the 4wd. The second recommendation is to replace the switch in the dash with GM Part # 15709327 @ $63.18 from GM. I replaced the switch last night and the problem is still there, but now all of the lights are lit up. The third solution is to replace the switch on the differential that actually sends the signal to the actuator. That GM Part # 88962315 @ $94.60 from GM. I am going to install it this evening and I will post my results then. I was told by the GM parts counter that this is something that they change out on a daily basis and they are sure that this will fix it. GM should recall this bad design and manufacture a good product for once.  

You have to remove the front drive shaft which is easily done by removing the 4 bolts in the front that hold the universal joints in. Then you remove the rear metal clamp from the rubber boot that is over the shaft entering into the differential. Pull the drive shaft forward while taking a flat head screw driver and carefully releasing the rubber boot from the shaft. After the drive shaft is removed, take out the 3 bolts that are holding the control motor to the transfer case. Be sure not to turn the gear since it is keyed to go back in a certain way. You would almost have to move it on purpose to do that though. (A GM dealer will print you out a step by step instruction on the disassembly of the unit itself on how to replace the sensor inside)Follow the GM instructions and reverse the installation process. It should fix your problem with the lights going out on the display and not engaging into 4wd. GM definately needs a recall!