1. Welcome To GMTruckClub.com!

    The #1 Chevy Truck Forum Online
    Online since 2004, we are the #1 Chevy Truck & SUV forum and user community. If you have any questions about your Chevy or GMC Truck, SUV or Crossover, or just want to connect with other GM owners and enthusiasts around the world, you've found the best place on the internet to do that.

    Join Today ~ It's Free
    Registering is Free and Easy! Hope to see you on the forums soon!

Transfer Case Problem

Discussion in 'GM Powertrain' started by Lil_Red_Chevy, Mar 5, 2011.

  1. Lil_Red_Chevy

    Lil_Red_Chevy Rockstar

    Hey guys, so I made the mistake of leaving 4wd hi engaged while changing out my automatic transfer case fluid. My transfer case was noisy before I changed the fluid so I just assumed nobody had changed out the fluid recently. So, I changed the fluid with the oem recommended Autotrak II and took it for a test drive. The 4wd will not properly engage and when I got back I had to top off the tcase again. I can hear the encoder motor working when I press the 4hi button and 4wd will engage atleast to some degree i.e. the front diff engages and I can hear the shifter. However, the 4hi button and 4low button just keep flashing when I try to engage each and my dash reads "Service 4wd."

    My question is: am I screwed?

    or do I just keep trying to engage 4wd to let the new oil work its way around the case. Isay that cuz my friend had a similar problem in his f150 but eventually it went away.
    1 person likes this.
  2. Lil_Red_Chevy

    Lil_Red_Chevy Rockstar

    I just tried changing the fluid again in 2wd this time and no difference thus far. I'm starting to think its the encoder motor itself. from what I've read they have a tendency to go bad on my particular tcase #246. Still if anyone has some experience with this I'd appreciate it.
  3. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    Take it to a shop that has a good scan tool. They can manually manipulate the encoding motor if it is OK. Will save you money in the end.
  4. Lil_Red_Chevy

    Lil_Red_Chevy Rockstar

    i figured id try that.
  5. Lil_Red_Chevy

    Lil_Red_Chevy Rockstar

    well just an update/fyi for anyone whom experiences a similar problem to the one I have listed here. It was the encoder motor and it turns out that it failed coincidentally after I changed the fluid. So, that means that the fact that I left in 4wd and drained it didnt have anything to do with it. However, next time I won't be taking any chances and I'll follow this policy: If its got selectable gears make sure they are disengaged when the fluid is changed just to avoid any possible headache down the road.

Share This Page