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Randy
Randy, GMC Technician
Category: GM
Satisfied Customers: 9765
Experience:  25 Years experience
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GM Suburban: Have a suburban that the transfer case broke.

Customer Question

Have a suburban that the transfer case broke. Got replacement transfer case checked tranny before installing transfer case. Reverse and drive worked. Put transfer case in car won't move
Submitted: 2 years ago.
Category: GM
Expert:  Randy replied 2 years ago.
Hi, my name is ***** ***** certified automotive professional with over 25 years experience. I will be glad to assist you with this.
Try putting the transmission in drive and then right back to park, you should hear a grinding noise if the transmission engages.
Does the transmission engage in gear?
Customer: replied 2 years ago.
There is a destinct grinding noise when going from drive to park. The transfer case you can turn at the input shaft and it turns freely. But when you put it together it does not work. Splines look good on the tranny and transfer case. Could a sensor be the problem?
Customer: replied 2 years ago.
We've actually seen the output shaft turn on the tranny for reverse and drive.
Expert:  Randy replied 2 years ago.
okay, that will be a problem with the transfer case. It sounds like the transfer case is in neutral. What is the year model?
Customer: replied 2 years ago.
2004 suburban z71 5.3l 4l60e
Expert:  Randy replied 2 years ago.
okay, thank you. Do you have all the connectors from the harness connected securely?Are the indicator lights lit on the 3-button shift control switch located on the instrument panel? Which position is indicated?
Customer: replied 2 years ago.
Wrong picture different transfer case than shown. There are three conector
Expert:  Randy replied 2 years ago.
Okay, that will be the NVG Transfer case, that model came with the Borg Warner and NVG options.
Customer: replied 2 years ago.
Yes there conected right and secure
Expert:  Randy replied 2 years ago.
okay, Are the indicator lights lit on the 3-button shift control switch located on the instrument panel? Which position is indicated?
Customer: replied 2 years ago.
Switch doesn't work all the time
Expert:  Randy replied 2 years ago.
okay, if the transfer case is good. Then that switch is probably commanding a neutral condition.
Customer: replied 2 years ago.
How do get transfer case out of neutral so I'll be able to drive it.
Expert:  Randy replied 2 years ago.
The transfer case motor/encoder consists of a permanent magnet (PM) DC motor and gear reduction assembly. It is located on the left hand side, driver's side, of the transfer case. When activated, it turns the shift detent lever shaft of the transfer case, clockwise or counterclockwise, to shift the transfer case. The motor/encoder is controlled with a pulse width modulated (PWM) signal by the transfer case shift control module. This circuit consists of a driver on both the Motor A and Motor B circuits. The encoder motor is bi-directional in order to allow the motor to shift the transfer case from 2HI or 4HI to NEUTRAL and 4LO positions. You can disconnect the motor/encoder and then see if it will engage. >number 3 on the diagram<
Customer: replied 2 years ago.
The shift motor was disegaged
Customer: replied 2 years ago.
Suburban won't move
Expert:  Randy replied 2 years ago.
There must be a problem with the case internally or the encoder motor is selecting neutral.
Customer: replied 2 years ago.
Good morning Randy, could our problem be the transfer case module? Our transfer case motor was tested good.
Expert:  Randy replied 2 years ago.
yes, that is possible. The module could be commanding the neutral condition.
Customer: replied 2 years ago.
Ok. The*****switch has a red light for N, which I assume is neutral. I tried to push the button for***** It flashes for about a minute but stays in N. Does that mean we need a module? Sorry for all the questions and thank you for all your help. Any help to get this thing out of neutral would be great :)
Expert:  Randy replied 2 years ago.
yes, that sounds like the most likely cause. If the control module is stuck on the N position then the vehicle will not move.
Customer: replied 2 years ago.
Ok. My wife will go get a module tomorrow and I will let you know soon. Thanks!
Expert:  Randy replied 2 years ago.
sounds good. Let me know if you need anything.
Customer: replied 2 years ago.
You shift into n transmission with brake and e brake on and push 2wheel drive. And the car shifts into*****thanks got it from owner manual
Expert:  Randy replied 2 years ago.
That's great news!
Please let me know if you need any other assistance.
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Thank you very much!