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4x4 not engaging front wheels 95 Tahoe

This is a discussion on 4x4 not engaging front wheels 95 Tahoe within the Technical / Maintenance forums, part of the General Discussion category; I tried doing a search, no matter what I search for, all I get is no matches found. Anyway, I've ...

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    4x4 not engaging front wheels 95 Tahoe


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    I tried doing a search, no matter what I search for, all I get is no matches found.

    Anyway, I've had some problems with my 95 Tahoe over the past year not engaging the 4x4. I've replaced/upgraded the actuator from the old thermal one to the newer electronic style. This solved that problem and now it engages the transfer case and turns the driveshaft. However, it seems that my front wheels are no longer engaging now when I shift into either 4HI or 4LO. I'm pretty sure the problem is the hubs/bearing, but I figured I'd ask and see if there could be anything else that might be preventing the front wheels from engaging.

    This is a fairly old truck with over 200K on it, so if there's anything I should replace while I'm doing the hubs, I'd love to know and do it so I don't have to go through this again when it snows.

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    Registered User woody2dtahoe's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Theres an actuator located on the front ifs diff too!!
    Last edited by woody2dtahoe; 12-25-2010 at 06:08 AM. Reason: beautyschool drop out for spelling!! LMAO
    97 Chevy Tahoe SAS project 14" lift 79 D60 kingpin AAM SF10.5
    96 Tahoe 6" superlift 3" BL
    99 Tahoe 4 door
    01 Honda RC51 ... too many mods!

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    Registered User fon1961's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    this is what i would like to get to address the problem:

    http://http://www.summitracing.com/search/?keyword=posi-lok&dds=1
    Last edited by fon1961; 12-25-2010 at 09:56 AM.

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    Registered User woody2dtahoe's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by fon1961 View Post
    this is what i would like to get to address the problem:

    http://http://www.summitracing.com/search/?keyword=posi-lok&dds=1
    Thats awesome .. im gonna be ordering one of those pretty soon, but the draw back is that the actuator on the front dif will still need to be hooked up electronically and relocated to somewhere in the engine bay to work properly. When you SAS an obs to make the "push button" 4wd drive to work the actuator needs to be removed from the 8.5 ifs unit and relocated. Ive been told that the Tcase actuator will not work if it doesnt sense the other actuator plugged in..
    My .02$
    97 Chevy Tahoe SAS project 14" lift 79 D60 kingpin AAM SF10.5
    96 Tahoe 6" superlift 3" BL
    99 Tahoe 4 door
    01 Honda RC51 ... too many mods!

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    Registered User fon1961's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    interesting, i've never heard that. if so, you would think that the kit would come with some kind of jumper to install instead.

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    Resident Dick Quyonmob's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by LDM666 View Post
    I tried doing a search, no matter what I search for, all I get is no matches found.

    Anyway, I've had some problems with my 95 Tahoe over the past year not engaging the 4x4. I've replaced/upgraded the actuator from the old thermal one to the newer electronic style. This solved that problem and now it engages the transfer case and turns the driveshaft. However, it seems that my front wheels are no longer engaging now when I shift into either 4HI or 4LO. I'm pretty sure the problem is the hubs/bearing, but I figured I'd ask and see if there could be anything else that might be preventing the front wheels from engaging.

    This is a fairly old truck with over 200K on it, so if there's anything I should replace while I'm doing the hubs, I'd love to know and do it so I don't have to go through this again when it snows.
    You've got it all wrong.

    Actuator engages the front diff, not transfer case.

    Hubs have nothing to do with 4wd in an IFS truck.

    1-When you shift the t-case you engage the front out put of t-case, making the front DS turn.
    2-Engaging the front output of the t-case triggers a ball switch on the top of the front t-case sending power to your front diff actuator.
    3-Front diff actuator engages the front differential sending power to the wheels.

    You likely have an issue with your wiring harness or the actuator switch on the t-case.

    Posi-lok is good, but not for people who don't understand how all the 4x4 system works together as you will be grinding it alot.
    Last edited by Quyonmob; 12-26-2010 at 08:26 AM.

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    Resident Dick Quyonmob's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by woody2dtahoe View Post
    Thats awesome .. im gonna be ordering one of those pretty soon, but the draw back is that the actuator on the front dif will still need to be hooked up electronically and relocated to somewhere in the engine bay to work properly. When you SAS an obs to make the "push button" 4wd drive to work the actuator needs to be removed from the 8.5 ifs unit and relocated. Ive been told that the Tcase actuator will not work if it doesnt sense the other actuator plugged in..
    My .02$
    This makes no sense. There is no actuator on the t-case, it is an encoder motor on a push button t-case. It requires no feedback from the differential actuator to operate the t-case.

    I had posi-lok, no foolishness like that.

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    Registered User woody2dtahoe's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by Quyonmob View Post
    This makes no sense. There is no actuator on the t-case, it is an encoder motor on a push button t-case. It requires no feedback from the differential actuator to operate the t-case.

    I had posi-lok, no foolishness like that.
    Sorry I stand corrected .. Everytime the push button 4wd doesnt work the shop replaces the "actuator" on the tcase .. or so ive been told. Sorry A buddy of mine SASd his 98 hoe and had to use the actuator off the front dif to get the Tcase to engage properly .. maybe just a quark in his truck ..
    97 Chevy Tahoe SAS project 14" lift 79 D60 kingpin AAM SF10.5
    96 Tahoe 6" superlift 3" BL
    99 Tahoe 4 door
    01 Honda RC51 ... too many mods!

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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by Quyonmob View Post
    You've got it all wrong.

    Actuator engages the front diff, not transfer case.

    Hubs have nothing to do with 4wd in an IFS truck.

    1-When you shift the t-case you engage the front out put of t-case, making the front DS turn.
    2-Engaging the front output of the t-case triggers a ball switch on the top of the front t-case sending power to your front diff actuator.
    3-Front diff actuator engages the front differential sending power to the wheels.

    You likely have an issue with your wiring harness or the actuator switch on the t-case.

    Posi-lok is good, but not for people who don't understand how all the 4x4 system works together as you will be grinding it alot.
    I might, I'm no expert on 4x4 systems. So that actuator I've already replaced engages the front differential? I doubt its the wiring, I've already checked everything there when i was installing the new actuator. Is there more than 1 actuator that might be causing the problem? Also, this is not a push button system, its the older shifting style.
    Last edited by LDM666; 12-26-2010 at 10:33 AM.

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    Resident Dick Quyonmob's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by LDM666 View Post
    I might, I'm no expert on 4x4 systems. So that actuator I've already replaced engages the front differential?
    I don't know. What did you replace? I wasn't there.

    Quote Originally Posted by LDM666 View Post
    I doubt its the wiring, I've already checked everything there when i was installing the new actuator. Is there more than 1 actuator that might be causing the problem? Also, this is not a push button system, its the older shifting style.
    There is only one actuator.

    If the actuator is new, it's likely the ball switch on the top of the front output. Which provides power to the actuator.

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    Resident Dick Quyonmob's Avatar
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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by woody2dtahoe View Post
    Sorry I stand corrected .. Everytime the push button 4wd doesnt work the shop replaces the "actuator" on the tcase .. or so ive been told. Sorry A buddy of mine SASd his 98 hoe and had to use the actuator off the front dif to get the Tcase to engage properly .. maybe just a quark in his truck ..
    Strangest thing I have ever heard of, as there isn't a feed back loop.

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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by Quyonmob View Post
    I don't know. What did you replace? I wasn't there.



    There is only one actuator.

    If the actuator is new, it's likely the ball switch on the top of the front output. Which provides power to the actuator.
    Ok, when I get back into town, I'll be getting her up on stands and checking things out. This gives me an idea of where to start. If I don't have to replace anything, all the better. Saving money is always a good thing.

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    Re: 4x4 not engaging front wheels 95 Tahoe

    Quote Originally Posted by Quyonmob View Post
    I don't know. What did you replace? I wasn't there.



    There is only one actuator.

    If the actuator is new, it's likely the ball switch on the top of the front output. Which provides power to the actuator.
    I also had one that had an open wire between the fuse box and ball switch, I could not find the open and ran a new wire.

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    Re: 4x4 not engaging front wheels 95 Tahoe

    Finally got around to fixing the problem. Turned out to be a problem with the spacer that came with the new actuator not engaging properly. Must have gotten turned or something when I put it in the first time, preventing it from working. Info was very helpful, glad I didn't have to replace anything and spend more money!

 

 

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