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Discussion Starter · #1 ·
I just about had a 911 in my 98 Suburban last night. I was stuck in 4 low. I finally got it to shift to 4 high. I would appreciate any tips &/or links. The push button 4wd has been acting up since last Saturday when I was stuck & couldn't get it to go into 4x4 mode. What are the proper procedures for putting it n 4x4 & taking it out?
We've had no problems prior to now. We just push the button when we want 4x4 & push it again for 2wd.
How does the 4x4 when needed button work? I used it on the way home after I got out of low lock.
Thanks
 

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You can only get into and out of 4WD Low from "Park" and "Neutral" (only when you are going very slow - basically stopped). 4WD Auto is for use in the rain or where you might have a little bit of traction, anyways. It lets the front and rear axles rotate at different speeds (like when making turns) so you don't get any "binding" between axles. The truck is also actually in rear-wheel drive until slip is detected, then the truck goes into 4WD. It happens very quickly, but if you pay attention, you can detect/feel/hear when 4WD is activated.
 

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Discussion Starter · #3 ·
Thanks,
Can you tell me about going into & out of 4wheel high?
Our indicator lights aren't working properly. Even the 2wd light isn't on all of the time. When I was trying to put it in 4 wd the light wouldn't come on even after it was engaged.
Last night I had to put the burban in reverse to get out of 4 wheel low. I ran through the gears a few times Park to low, before it disengaged.
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Original owner? If not, look through your service records and see if your encoder motor has been replaced. The encoder motor is the black cylinder located under the tcase and performs the shifting. It could be that the wiring harness was trashed by the installer, like mine was, and it is causing the shifting problems. A good starting point is to make sure all electrical connections are solid.

Next, check all 4x4 system related fuses. Someone can correct me if I am wrong, but I think a blown fuse will trigger a Service 4WD lamp on your dash. You dont have the Service 4WD lamp, do you?

Otherwise, it may be the encoder motor. Some in the transmission industry have told me that the actuator motor will develop a flat spot on the armature and cause motor failure. I don't know if I buy that or not, but something to think about nonetheless. I hear the 4x4 switches are not very likely to fail.

My encoder motor failed after an oil change of all things. The tcase went to 4low and stayed there. About $500 - $600 for the encoder motor. No Service 4WD lamp to tell me the motor had failed (which is why the dealership trashed the harness looking for a broken connection before they stumbled upon the encoder motor. Ironic, eh?).
 

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Discussion Starter · #5 ·
Like everybody else I like the convience of the electronics, but I hate the crap. Give me a floor shifter & lock-outs any day. At least I know when I'm in or out.
I don't have a service lamp on.

what's the proper procedure for going into & out of 4 wheel high?

Super I just can't imagine a dealerships highly trained techs doing you that way. I'm just amazed. While there are most definately good techs out there, it's hard to gaurantee that they will actually be the ones performing the work on your vehicle. I hate to pay big bucks for somebody to figure something out just like I would. I'm paying big bucks because they have learned their **** & are worth the money. Quite frequently that is far from the truth.
 

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For 4HI just push the 4hi button whenever your moving below 65 or 70 MPH. For 4LO you need to be going 2-5 MPH in neatral. Sounds like you have a bad switch. An encoder motor can also cause this. If you blow a fuse the service 4X4 light will NOT come on(trust me I know, buddy has a 99 with the autotracCensored). GM has a bulletin to replace the switch for 4X4 problems on the autotrac system. The encoder will normally make the system not work at all, but the indicator lights with no service 4X4 light sounds like a switch.
 
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