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Trans Problem 99 GMC Sierra

Discussion in 'Chevy Trucks' started by ACL&L Plowing, Dec 4, 2005.

  1. ACL&L Plowing

    ACL&L Plowing Junior Member
    Messages: 29

    Trans Problem 99 GMC Sierra 2500 --------------------------------------------------------------------------------

    One of my guys made the mistake of shifting the trans into 4wd while the truck was moving and in Drive. Now the front end is vibrating when traveling about 25 mph or more, sounds like something is grinding. It is OK when truck is switched out of 4 wd into 2 wd. What could this be? It is a 99 GMC 2500 Sierra. What might it cost?
  2. ACL&L Plowing

    ACL&L Plowing Junior Member
    Messages: 29

    More snow tomorrow, need help. Thanks
  3. NJBuickRacer

    NJBuickRacer Member
    Messages: 59

    Could potentially be a transfer case problem, it's difficult to diagnose something like this without actually seeing the vehicle.

    REAPER 2000 Club Member
    from 60050
    Messages: 2,230

    Shifting on the fly should not cause any problems. Check wheel balance wieghts.
  5. Check U joints

    Check front U joints, that truck should be able to shift on the fly! Is it the old body style or the New body style! My 1999 old body style, i can throw into 4x4 on the highway!
  6. gcsupraman

    gcsupraman Senior Member
    Messages: 110

    Agreed - I did it all the time.

    Is their oil in the front dif?