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Discussion Starter #1 (Edited)
I have a problem whit my 1998 chevy suburban k1500 it drop into 4x4 low when i have the auto 4x4 feature and it losses traction in one wheel instead of just remaining on 4x4 hi, it also does not stay on 4x4 after you turn off the sub it divert back to 2 hi. I was told it is the transfer case motor any other suggestions.
 

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Welcome to the Club!! Sorry, I do not know the answer to your question, so hopefully this bump will catch someone's attention soon.
 

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It's an interesting problem, and, I'm not sure I have much of a suggestion.

Does it really drop into 4L? Because the H-L shift isn't synchronized, I would expect that it would have a real hard time dropping into L under any kind of power. I could see it going from 4A to 4H. If it's really dropping into 4L randomly, that suggests something is wrong with the electronic system (whether the module, or the switch, or something) because it would be bypassing all of the failsafes that are built into it (like the transmission needing to be in N) to prevent it from shifting between H and L under power.
 

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Welcome to the club. As MrShort said are you sure it going into 4L. Usually it wont go into 4L until you are stopped and have the trans in neutrel. I would think if it is going into 4L while the truck is moving its making a hell of a grinding noise.
 

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What they said. If you try to shift ranges in gear under power there will be some noise if you're lucky, destruction if you're not.
 

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Discussion Starter #6
Well it my not be 4L but it shore feels like it it. it seams that some one drop and anchor behind me but as soon as i stop and place it on parking it disengages
 

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I've been told by almost everyone that has a Chevy with the 4x4 auto function to NEVER use it while driving, cause they keep telling me horror stories of when they drive and one tire hits a spot of no traction, the 4x4 system engages and sends them into the ditch every time.

I don't like the 4x4 auto function, if you can avoid using it, then do, cause the PCM is going to dictate when you need your 4x4 to come on, and it can come on any time you loose traction to one tire.

Can you be a little bit more specific on what its doing, what tire is doing it, when it's doing it, and what your doing when it does it?
 

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The auto 4x4 should ownly be used in snow, mud or slick roads.
 

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Well it my not be 4L but it shore feels like it it. it seams that some one drop and anchor behind me but as soon as i stop and place it on parking it disengages
That sounds more like the drivetrain is binding rather than the transfer case is shifting ranges -- like driving in 4H on a hard surface. In 4A, when the computer detects a rear wheel slipping, it engages a clutch inside the transfer case then releases. It sounds more like that clutch is not releasing.

1st thing I might suggest checking is the fluid level/condition in the transfer case.

Any chance you have an odd sized/mismatched tire? I've seen 4wd systems bind up over an odd sized tire.

Is it more prevalent while cornering?
 

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Discussion Starter #10
That sounds more like the drivetrain is binding rather than the transfer case is shifting ranges -- like driving in 4H on a hard surface. In 4A, when the computer detects a rear wheel slipping, it engages a clutch inside the transfer case then releases. It sounds more like that clutch is not releasing.

1st thing I might suggest checking is the fluid level/condition in the transfer case.

Any chance you have an odd sized/mismatched tire? I've seen 4wd systems bind up over an odd sized tire.

Is it more prevalent while cornering?
Thanks for your help i will have the oil check on the transfer case. you just hit the spot that what it does exactly. what do you recommend change the oil and some kind of additive or have transfer case work on.
 

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I would start by checking the fluid. When I first bought my '98, I had some minor issues with the 4A function. The Autotrac t-case is pretty sensitive to fluid. When I bought my '98, I was having some minor issues with the 4A function (not near as extreme as yours though). When I checked the fluid I found "pink" fluid instead of the specified "blue" fluid. If you find anything other than a clean blue fluid, drain and refill.
 
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