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transfer case shifting, but no front drive?

Discussion in 'Chevy Trucks' started by ontario026, Jul 16, 2014.

  1. ontario026

    ontario026 Senior Member
    Messages: 228

    as the title says, my transfer case is shifting, but the front tires won't put power to the ground... rear tires just spin, but front don't drive.. 4hi seems just like 2hi, but in 4lo I get the gear reduction, but no front axle pulling...

    Caused a lot of tire smoke today pulling out big boats with no front axle engagement....

    any idea what's wrong??

  2. kimber750

    kimber750 PlowSite Veteran
    Messages: 3,166

    Actuator on front axle not engaging.
  3. gc3

    gc3 Senior Member
    Messages: 713

    Vacuum lines on actuator
  4. jb1390

    jb1390 Senior Member
    Messages: 710

  5. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,746

    Not on a gm trk
  6. 1olddogtwo

    1olddogtwo PlowSite Fanatic
    Messages: 11,394

    Muffler bearing need grease.

    Perhaps if they used vac lines from the factory it would give reason to replace them. I don't know, I'm a ford guy with vac hubs.
  7. gc3

    gc3 Senior Member
    Messages: 713

    I guess I should have said " actuator and possibly vacuum lines " my bad
  8. 99LsSilverado

    99LsSilverado Junior Member
    Messages: 18

    More then likely the encoder ring in the transfer case motor has gone bad and needs replacement. The best thing is to replace the whole motor instead of just the ring.
  9. jb1390

    jb1390 Senior Member
    Messages: 710

    To the OP, I'm assuming you have gotten underneath the truck to verify that the t case is actually engaging (front driveshaft will be locked to the rear wheels, front wheels rotate freely) I am assuming you have, since you told us that the t-case is engaging fine.

    If this is true, then it is not the encoder motor as has been suggested.

    There is also an actuator in the front axle that locks the wheels. This is electronically controlled, it is not controlled via vacuum lines. There are posts on how to test it using a socket installed behind the actuator, if you do a search. Also verify you have voltage to that actuator when 4wd is engaged.