GMC Jimmy transfer case encoder motor install 97

rrrccc01rrrccc01 Member Posts: 5
edited July 2014 in GMC

I am about to replace the transfer case encoder motor on my 1998 GMC Jimmy NP1.

I have the typical engage 4x4 problem: I disconnect TCCM or unplug battery for a few minutes,
turn on/off the ignition 5 times and then works for a little while and then no more.

I have replaced the

vacuum actuator (new)
front axle coupler sensor (new)
TCCM (junk yard)
dash switch (junk yard)

in the above order; so now…

I have acquired a new transfer case encoder motor and about to install it. I read a post in another
news group that says:


Lucky way - Only thing that needs to be removed is the encoder motor itself. Tools needed are a
10mm hand wrench and a 8mm and 10mm socket wrench. The 10mm socket will work on the
upper and lower bolts, while the regular wrench is needed for the middle bolt. (Tight squeeze).
The 8mm socket is for the electric plug.
Then, just pull out, and wiggle it out of the truck. Install in reverse order.

Unlucky way - This means the encoder motor did not just wiggle out. Now the front drive shaft
will have to be removed at the transfer case. Then, a yolk puller is needed in order to remove
the yolk from the transfer case. Once this is done, go to the directions in lucky way.

The above process was for a 1997; does it still apply to 1998?
Are there any secrets to this process?
Can I influence the lucky/un-lucky way?

Tanx in advance.



  • repairdogrepairdog Member Posts: 948
    Sounds about it but you should have the CV type rear joint for the front drive shaft so remove the 4 front bolts on the u-joint (front diff end) and push the shaft back and front drops off, then the rear CV has a hit to release internal snap ring so with a block of wood and a 3 lb hammer hit it forward (towards front or diff direction)and the snap ring releases and the rear (transfer case end) pulls off so now you can access the encoder bplts.
  • rrrccc01rrrccc01 Member Posts: 5

    Tanx for the reply. From the number of your posts sounds like you've done this before! So here's my question, how often does the encoder just "wiggle out"? Fifty/Fifty? Better, worse?


  • mkobmkob Member Posts: 10
    I just replaced my transfer case in my 99 GMC Jimmy 4x4. Now when I drive with the A/C on the power is just about zero. I seem to have massive loss of power after the change of the transfer case while my A/C is on only. What can be the cause of this?
  • kaczkacz Member Posts: 2
    My truck is and 2001 GMC SLS Sonoma X-cab:

    It has the pushbutton 2WD/4HI/4Low buttons on the dash, its a 6cyl with the 4 speed auto trans.

    My problems is this:

    Used the 4x4 in HI range this past weekend on my property to pull some old tree limbs to the dump and also at my friends place as well. No off roading or any of that stuff just used it to get up the lawn instead of tearing it all up.

    Now I'm having issues with the 4x4 disengaging, it goes back into 2 HI but the transfer case is staying locked in. I can move/spin the front shafts but the shaft that goes to/into the transfer case doesn't move or spin at all. It used to move freely when in 2 HI but now it doesn't.

    All my tests that I have done so far is with the truck sitting on the ground running and in park.

    I know the 4x4 front shafts are disengaged because the wheels move freely across the pavement. When engaged they do the chopping and sliding event. THIS not my problem its to the transfer case is where its all happening.

    I am having a lot of drag on the road to the point its eating my gas mileage, there is a slight vibration and I have to lean into it to get it moving.

    One tranny shop told me it could be some plastic pins or bushings in the transfer case or possibly a fork or two that are going/have gone bad. Without opening it up they cannot tell me what it could be. The price could be a 100 or 200 up to a grand for a used rebuilt transfer case installed.

    thanks in advance
  • bigmac79bigmac79 Member Posts: 1
    I dropped the rear driveshaft on my 97 GMC jimmy due to a failed u joint and i was wondering how i get the drive shaft off to replace the u joint
  • dirtyvegasdirtyvegas Member Posts: 1
    ok i have a 97 jimmy and the front hubs are not locking in the transfer case goes in to 2hi 4lo and 4hi i just dont know what to do and the snow will be here soon if someone can help me thank you
  • needhelp001needhelp001 Member Posts: 1
    I am replacing a transfer case motor on my 99 ford explorer, but do not know how to get the wires out of the transmission?
  • sparki3sparki3 Member Posts: 1
    have you found out anything yet? i have a 2000 gmc jimmy/envoy 4x4 and the front drive shaft is not turning freely in 2hi, it engaged at all times, front axles do turn freely. trying to solve my problem also, sounds like we have the same issues. thx and good luck. sparkie
  • gyakegyake Member Posts: 2
    what is the difference between a orange and a blue plug on the 4x4 module that is located behind the right kick panel. I have an orange , but the only replacement I can find is blue. I also have 2 plugs that look like they go into the module but all replacements I can find just have one????
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