Yukon 4x4 Help

Discussion in 'OT Driven' started by chrish04, Jul 27, 2008.

  1. chrish04

    chrish04 New Member

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    I have a 99 Yukon, and after playin in the mud today when i went to put it into 4x4 low it makes a loud clanking sounding when it engages and disengages from 4x4 low to 4x4 high, if anyone has any ideas on what might be making this sound it would help alot.


    Thanks,
    Chris:sadwavey:
     
  2. IHAVECRABS

    IHAVECRABS Diversity is our strength. LOLOL

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    -if you sank it in water/mud, there might be water in your transfer case fluid

    -make sure youre engaging 4wd low right by putting it in neutral first

    but really, it could be quite a few things. u joints, hub assembly, etc.
     
  3. squid

    squid braap

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    My Av does that, I thought it was the front hubs locking and unlocking. :dunno:

    Under what conditions are you using low range in a Yukon? I've never seen a real use for it in such a big truck.
     
    Last edited: Jul 28, 2008
  4. Sandjunkie

    Sandjunkie New Member

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    Only on a stick, if its an auto, Park is the right gear.
     
  5. IHAVECRABS

    IHAVECRABS Diversity is our strength. LOLOL

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    park, neutral...same affect.
     
  6. P07r0457

    P07r0457 New Member

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    my chevy goes into 4Lo when in neutral and foot on the brake. I've never tried doing it in park. Seems pointless to do so.
     
  7. Sandjunkie

    Sandjunkie New Member

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    Because an automatic will turn the output shaft in neutral if allowed, it can cause alot of grinding when engaging low range. Whereas if you keep it in park, the output shaft is held and wont be turned by drag of the geartrain inside the auto.
     
  8. deusexaethera

    deusexaethera OT Supporter

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    Park is just Neutral with a locking pin that drops into the teeth on the output gear. It doesn't accomplish anything that holding the Neutral + Brakes doesn't accomplish, but it's an academic point anyway -- you still have to shift out of gear first.

    I'm not sure why you say the output shaft will turn in Neutral, Sandjunkie. As long as the wheels are stopped, the output shaft will be stopped.
     
  9. Sandjunkie

    Sandjunkie New Member

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    Except that in New Process transfer cases that Chevy uses, you go through neutral in the transfer case between 4hi and 4lo. If you spend too much time with both the T-case and Transmission in neutral, the whole assembly will turn and you will have gear clash when you finally get it engaged into 4lo. An old coworker of mine did it a few times... enough that we called it a Mondo. If you are fast between 4hi and 4lo, its not a problem but not everyone is quick. ;)
     
  10. deusexaethera

    deusexaethera OT Supporter

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    Aha...Yeah, I can see how that would be an issue then. I didn't think that in a part-time 4WD setup, the output shaft on the transmission isn't really an output shaft, but more of an intermediate shaft.
     
  11. Sandjunkie

    Sandjunkie New Member

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    But we still call it an output shaft since it is, if you'll forgive the poor grammar, outputting the power from the transmission to the transfer case.
     
  12. thematter

    thematter New Member

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    my 96 tahoe makes the same clunk noise, make sure its in neutral and not moving at all.
     
  13. deusexaethera

    deusexaethera OT Supporter

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    Might be better to call it the "transfer shaft" or something, since it transfers power from the gearbox to the transfer case. But I get the feeling I'm not going to turn decades of convention on its ear just by saying so.
     
  14. Sandjunkie

    Sandjunkie New Member

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    Not really since they are 2 separate units. That being defined by having two separate oil sumps. If you really want to change it, feel free to bitch to SAE, till they change the nomenclature, it's an output shaft.
     

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