1992 GMC Suburban K2500 Questions

Discussion in 'GM Powertrain' started by andrewlail76, Sep 3, 2009.

  1. andrewlail76

    andrewlail76 New Member

    1. I can shift into 4WD High and out with no problem(other than a slight delay of going into 4wd), but I have to force it into 4WD lo...and wheh I shift it out of 4 Lo only...it is a forced shift and it makes a grinding noise. Why?

    2. When I cold crank it, it will sputter and cough like crazy...but after a few minutes...after it warms up...it clears up...
    Beyond the cold crank up, no more sputters or loss of power

    I guess that is it for a start.
    Here is "The Beast":

  2. unplugged

    unplugged Epic Member 5+ Years 1000 Posts

    Probably an actuator problem on the transfer case. The actuators have a known issue. You can either get a replacement from Napa for $70 or buy the "new" actuator and harness for big $$. I went with the stock replacement from Napa.

    Don't know what's going on with the cold start issue. Plugs or wires might be a good place to start.
  3. andrewlail76

    andrewlail76 New Member

    Is the actuator an internal part? Will I have to lower the transfer case and open it up?

    I'll try the plug wires as a start
    The previous owner changed the wires every time he replaced the plugs
  4. andrewlail76

    andrewlail76 New Member

    Come on guys...where is the actuator in the transfer case?

    Also...give me a recommendation for a muffler

    Flowmaster 50 Series? That would be aggressive but not too loud on the inside...right?

    I have single, not dual, by the way.
  5. notpilbrisk

    notpilbrisk Member

    I have a 92 k2500 burban as well. Are you in park when trying to shift out of 4lo. I made the mistake of putting my truck in nuetral and shifting out of 4lo and had the same problem. I then put it in park and shifted out NO problem! : )
  6. unplugged

    unplugged Epic Member 5+ Years 1000 Posts

    I searched and could not find the post I had made with the pics, but here is one that shows the actuator.
  7. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts


    The actuator that unplugged is talking about IS NOT on the transfer case! If your 4HI works, the front axle actuator is fine. They can be trouble, but they have ABSOLUTELY NOTHING to do with getting your case in 4LO.

    First of all, check your T-case fluid. Those cases are notorious for misting off the ATF till they are dry/nearly dry. Drain the case, try to keep track of how much comes out. They only hold two quarts. Fill the case with Synthetic Manual Transmission Lube. BTW, make sure you can get the fill plug out BEFORE you drain the case.

    As for the rough shifting, it's most likely from non-use, and possible lube starvation. There is a planetary gearset that rides on the mainshaft of the case. This slides back and forth to give low range reduction. If it hasn't been used for a long time, it could be sticking, or the shift rail could be sticking. Hopefully with use and fresh lube it will start to work better.

    For shifting technique, you need to learn what works for you and your truck. The general instructions are to have the trans in nuetral, and make a quick smooth shift from 2Hi directly to 4Lo. Do not stop at nuetral, do not collect $200. Sometimes they shift better if the truck is rolling slowly. A little gear noise is normal, and nothing to be concerned with. Remember, it's a non-synchronized gear set.

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