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4wd grinding

Discussion in 'Chevy Trucks' started by jrm123180, Jan 16, 2008.

  1. jrm123180

    jrm123180 Senior Member
    Messages: 156

    Ok, I'm having a problem with my 79 Chevy 1/2ton pickup.

    When I have it in 4wd and I'm pushing snow...if I'm up against (for example) a snow bank and my front wheels spin, I hear a grinding, sounds like it coming from the front pass side wheel...any suggestions? Could the gear in that wheel be worn?

    Also, I'm suddenly having difficulty getting it into 4wd. I have a NP203 on it with the part time conversion kit. I can get it into 2hi and 2low with not problems...has been fine up until this last storm...could i be in need of fluid possibly our our of adjustment? I don't shift it until I'm just rolling in neutral and like I said, this is something just suddenly began happening.

    Any thoughts?

  2. derekbroerse

    derekbroerse 2000 Club Member
    Messages: 2,377

    For a time I had a similar sound... until I stripped it out entirely. Mine was the splines on the front driveshaft, under certain load conditions, the worn portion was getting bad enough to ratchet over itself... not good, needed to be rebuilt by a drivetrain shop.

    Check to see how much movement there is in there if you grab and wiggle it around. Its supposed to be tight and not really move at all. Mine was sagging enough to even cause an imbalance when driving at speed in 4wd, or 2wd with the hubs locked.
  3. streetfrog

    streetfrog Senior Member
    Messages: 337

    Also check your tires. They all need to be the same size diameter. ! might be low or you could be running dif tires. Just a possibility .