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4wd or locking differential engaging while driving

Discussion in 'Chevy Trucks' started by bswalks, Sep 6, 2011.

  1. bswalks

    bswalks Member
    Messages: 59

    Hey all. I've got a 2005 hd2500 issue i need some help with.
    Twice in the past 2 days i've been driving & it feels like the 4wd has engaged by itself.
    Truck pulls hard to left & i get some wheel hop, as if its in 4wd.
    I immediately pull over, back up & i hear a loud clang, like the locker is disengaging.
    If this ? has been asked before, my apologies, i'm new to the forum.
  2. BlizzardBeater

    BlizzardBeater Senior Member
    from Maine
    Messages: 420

    Check to see if you have a frozen brake caliper. Jack the wheel off the ground and try to spin the wheel.
  3. bswalks

    bswalks Member
    Messages: 59

    Thanks for the info. I'll check that out
  4. woodchuck2

    woodchuck2 Senior Member
    Messages: 304

    Check the air pressure between the rear tires. That alone can engage the G-80 when turning. Mine locks up all the time when turning on wet roads and sometimes on dry roads if the truck leans into the turn at all. May not hurt to pull the cover and make sure it is not damaged.
  5. bswalks

    bswalks Member
    Messages: 59

    Hey, thanks. I'll try that too.
  6. mossman381

    mossman381 2000 Club Member
    Messages: 2,410

    Could be the transfer case encoder. I know my dad has a problem trying to get his 04 out of 4 wheel drive. It will bang out of 4x4 if he does not back up after taking it out of 4x4. Never had a problem going into 4 wheel drive. And no 4 wheel drive light, but I am leaning towards the encoder.

    Here is a link to LMC parts http://www.lmctruck.com/icatalog/ce/full.aspx?Page=153
    Last edited: Sep 7, 2011
  7. ratherbfishin

    ratherbfishin Senior Member
    Messages: 205

    I had what sounds to be a similar issue with my 05 HD...It was the r/e locker...changed the r/e gear oil and no problem since.Easy fix and a good idea to do anyways.Just make sure you get the correct gear oil !
  8. bswalks

    bswalks Member
    Messages: 59

    Hey, thanks to all! Appreciate all the help.
    I've checked the calipers & tires- seems ok.
    Ratherbfishin, your the second to tell me to
    service the rearend. It's never been changed, so that's next.
    Thanks again!!