How to fix 4wd problems on a 2001 GMC Jimmy?

[T-Rex]

We recently purchased a used 2001 GMC Jimmy 4wd and the 4wd was not engaging we had to take it th GMC because no one else could do the diagnostic test. Our ABS light is also on, GMC charged us a little over 800.00 to put in a acuater and then a week or so later it started with a loud whistling noise and then when we tried to put it in 4hi the lights kept blinking back in forth from 2hi to 4hi. We took it back to GMC who said that it was the switch and the transfer case fluid was leaking sucked up into all the ac and heating lines. They want to charge us over 1,400 now to fix it which we cant. Anyway is there anyone out there familiar with the 2001 4wd problems and how I myself might be able to repair the fluid in the lines. I already put the switch on. Nothing but a money pit so far. I wish I had never bought it. Please help at my wits end and cant trust nor afford GMC anymore.Thanks

 

[Molson02536]

We recently purchased a used 2001 GMC Jimmy 4wd and the 4wd was not engaging we had to take it th GMC because no one else could do the diagnostic test. Our ABS light is also on, GMC charged us a little over 800.00 to put in a acuater and then a week or so later it started with a loud whistling noise and then when we tried to put it in 4hi the lights kept blinking back in forth from 2hi to 4hi. We took it back to GMC who said that it was the switch and the transfer case fluid was leaking sucked up into all the ac and heating lines. They want to charge us over 1,400 now to fix it which we cant. Anyway is there anyone out there familiar with the 2001 4wd problems and how I myself might be able to repair the fluid in the lines. I already put the switch on. Nothing but a money pit so far. I wish I had never bought it. Please help at my wits end and cant trust nor afford GMC anymore.Thanks

The Vacuum switch on top of the transfer-case you can replace your self, the part is just under $45.00 at Auto Zone, Parts Source or Napa. It's a PITA to replace with an open end wrench by flipping back and forth, but can be done and it's located on top of the transfer-case on the driver's side and takes about 30 min to replace.

Just un-clip the three vacuum line fitting and then undo the 4wd Vacuum switch and install the new one. As for the transmission oil in the lines, it will make it back in the then engine and be burn out though the exhaust. Is some cases you may have vent control issues till the transmission fluid works it way through your vacuum line system. If you still have transmission fluid throughout your vacuum lines, use a little http://www.seafoamsales.com/ to clean out your vacuum.

As for your ABS light being on, it's likely going to be a dirty sensor or a bad wire leads to the sensor. In the wost case it's going to be a front wheel bearing going bad and the sensors are rubbing the speed ring from a miss aligned wheel hub. This will be costly and also a PITA to replace due to the years of corrosion from winter salt collecting up front of the Jimmy.

Start with removing the front wheels and inspecting the wheel sensor and the wire leads for any damages like corrosion or broken wire, if there is no signs of damages. Spray it down with brake parts cleaner really good and this should fix the ABS issues unless it's the ABS module it self or the ABS electric pump. If you take the Jimmy to Auto Zone i think they still scan for the DTC codes free of charge, but i have heard that some places don't anymore.

Here is few links that should help you get our Jimmy running 100% again soon that you can do your self. Be safe and keep us posted.

http://gmcowners.com/gmc-forum/showthread.php?t=14184
http://gmcowners.com/gmc-forum/showthread.php?t=13770