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NEED HELP Driving with AWD. Any hints?

Discussion in 'Technical Discussion' started by Zeus101159, Apr 18, 2017.

  1. Zeus101159

    Zeus101159 Member

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    I've been driving pickups for 35+ years and 4x4's for 20. Recently acquired a 2004 Yukon Denali with AWD and am having some issues.
    Is there any way to keep it locked in???

    Just snowed 12" of wet heavy snow and I'm trying to back up an incline. Spins, locks in, grabs traction, kicks out, spins ... stuck. Go forward. Try again. Repeat.

    Couldn't keep it pinned or I would have launched out of an alley

    THIS is gonna get old ... quickly.

    Anyone can give me some pointers on how to drive an AWD?
    I will be most appreciative!
     
  2. littleblazer

    littleblazer Gold Supporter

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    The only one I have experience with is the escalade and that is a full time iirc.
     
  3. Tiggerr

    Tiggerr Gold Supporter

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    Escalade and Denali are pretty much the same truck...

    What the op is describing does not sound right to me at all...
    I've never driven a GM AWD in the snow but anything else I ever have didn't behave that way at all... I'm thinking something is out of whack...wheel sensors, encoder, t-case unit, diff, something isn't right....
     
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  4. AWD V8

    AWD V8 Well-Known Member

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    Are you driving in auto-4wd or full time 4wd?

    If your truck is like mine, '03 Envoy, if you have it in auto-4wd the computer determines when to complete the 4wd coupling based on wheel spin. From my experience with this, it takes a fair bit of wheel spin to lock up. If I just give it enough gas the rear wheels will simply dig a hole. If I gas it more and more the computer begins to lock and I feel the truck lurching repeatedly as it's on the brink of completely locking. Once I get to a certain MPH, about 10-15 it locks up and drives the front wheels.

    The G80 diff works the same way although it doesn't use a computer, just RPM. In 2wd giving it just a bit of gas it will dig a hole with one wheel. The RPM needs to go up and then the diff will start to drive the other wheel.

    So in auto-4wd on snow, wet grass, whatever, if I just give it a bit of gas it will simply dig on hole.

    In 4wd it will drive the front wheels as well as the rear. So, if I give it just a wee bit of gas, it will apply power to one rear wheel and to one front wheel. Those wheels will dig holes until I give it more gas, then the G80 kicks in and now drives both rear wheels.

    I've found that this is normal with my truck, and the others I've driven.

    The auto-4wd was intended for driving around the city in poor weather so you wouldn't damage your drive train by driving in full time 4wd.
     
  5. dkvasnicka

    dkvasnicka Silver Supporter

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    If the AWD system in 2004 Yukon is any similar to that found in GMT360s then I'm afraid what you're describing is normal.

    When I had my 9-7X with all four corners in the air the AWD system detected immediate slippage, engaged, let all 4 wheels "grab" for a while, slowly disengaged and this all was repeated indefinitely in a few seconds intervals...
    If your traction circumstances were so extremely bad that it resembled spinning the wheels in air then maybe the TCCM was just displaying the same type of "thinking".

    In situations where the AWD system helps the truck get traction and propels it forward I don't really notice this and would say the AWD system does its job properly but what you're describing must be frustrating...
     
  6. Mooseman

    Mooseman Moderator

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    If you have a selectable 4x4 system, use 4hi to keep the front wheels engaged. If you don't have a switch, then it's the automatic part-time AWD system, which I call the slip-bang system. It detects slip on the rear wheels, it will bang in the front wheels momentarily and disengage them a few seconds later. Same thing if you have the switch selected to 4auto.
     
  7. littleblazer

    littleblazer Gold Supporter

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    It should be a full time system is what I'm getting at unless it's selectable. It's a viscous coupled type transfer case so power always is split.
     
  8. Tiggerr

    Tiggerr Gold Supporter

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    Pretty sure it's not selectable on the Denali and Escalade... it's just full time "auto"
     
  9. littleblazer

    littleblazer Gold Supporter

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    On our Escalade it is always on, not auto like the awd 360s. I don't know about the Denali system but I assume it is the same or similar. In 07 it switched to a more auto system where it changes bias I believe. But the Denali was available with a selectable 4wd too, Escalade not so much. I doubt it is since it was an uncommon option on what was considered a Luxury vehicle. Sorry I am being unclear, hopefully that helps. It should not be engaging and disengaging like it is.
     
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  10. Tiggerr

    Tiggerr Gold Supporter

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    Didn't know the Denali was offered selectable at all..

    I know my buddies Escalade has no switch at all for the AWD/4WD... it's just always there...
    another friends Yukon Denali was like that too... no switch at all...

    Either way something doesn't sound kosher with the op's description of how it acts..

    So glad my Rainier is 2wd lol
     
  11. littleblazer

    littleblazer Gold Supporter

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    Maybe I'm thinking of the regular Yukon then. Either way, not right.
     
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  12. Zeus101159

    Zeus101159 Member

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    Like I stated I've driven 4x4 for a long time. But they all had either a mechanical shifter or an electrical one to engage the 2w/4HI/4L

    This is Automatic and it could have been the circumstance I guess.

    I've driven a 2014 4x4 Yukon and it has a selectable switch. 2 wheel/Auto/4x4.

    This Denali has no switch.

    I got it with a stone dead battery, is it possible it needs to "re-learn"?
    Not sure if that even makes sense lol

    The engaging/disengaging is extremely frustrating!

    EDIT: "So glad my Rainier is 2wd lol"

    You wouldn't be if you lived where I live. Just finished getting 16" of wet heavy snow. 2 wheel drive vehicles in ditches/stuck in middle of streets everywhere for 3 days till it started melting. Been there, done that.

    EDIT2: I don't think a full option Escalade of the same year came with anything different than the full option Denali other than badges ... and price tag.
     
    Last edited: Apr 20, 2017
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  13. littleblazer

    littleblazer Gold Supporter

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    So then there's an issue. I would suggest checking the fluid level first? I don't believe there is any electronic controlling of the engagement... It is fluid coupled iirc.
     
  14. dkvasnicka

    dkvasnicka Silver Supporter

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    To be honest I think most of this is because of tires, not because of 2WD :wink:
     
  15. Mooseman

    Mooseman Moderator

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    Or an interface problem between the seat and the steering wheel :biggrin:
     
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  16. Zeus101159

    Zeus101159 Member

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    "To be honest I think most of this is because of tires, not because of 2WD"

    Some of it is I'm sure or inexperience but having driven 2wd pickups for a long time I am well aware of their limitations. But then they were 2wd RWD. Front wheel drive is different for sure.

    "Or an interface problem between the seat and the steering wheel"

    ^^ That is probably the problem :wink:

    I'll check the fluid. I can see that being a problem if its liquid coupled. TY for the suggestion!
     
  17. Tiggerr

    Tiggerr Gold Supporter

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    That's the majority of all driving issues....
    Loose nut behind the wheel!
    Lol
     
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  18. Zeus101159

    Zeus101159 Member

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    Very true ...
     

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