Four wheel drive problem

Which of these does your vehicle have ?

Transfer Case - NVG 233-NP1 (Two Speed Selectable)
Transfer Case - NVG 136-NP4(One Speed Automatic)

The New Venture Gear NV233 is an electronic shift transfer, with the following three modes of operation, Two-wheel drive high range, Four-wheel drive high range, Four-wheel drive low range. The gear reduction for low range is provided by a planetary gear set. The floor-mounted shifter has been eliminated. A switch, located on the upper right side of the instrument panel, is used to select the operating range. The indicator lamps on the switch show the current mode of operation. When the four-wheel drive has been selected, the four-wheel drive indicator lamp on the switch is designed to turn on when the front axle has engaged.


Automatic Transfer Case
The single speed automatic transfer case system shifts automatically from rear wheel drive to four wheel drive when the transfer case shift control module (TCSCM) senses the difference in rotation speed of the front propeller shaft and the rear propeller shaft . Two vehicle speed sensors, one located at the rear output shaft area of the transfer case, and the other, located at the front output shaft area of the transfer case, send front and rear propeller shaft rotation speed information to the TCSCM.
When the front and rear output shaft rotations remain the same, the TCSCM sends pulse width modulation signals to the encoder/motor to keep the transfer case in rear wheel drive. When the front and rear output shafts rotations are different, the shift control module sends pulse width modulation signals to the encoder/motor to engage the transfer case into four wheel drive.
The system will automatically transfer a percentage of torque to either the front or rear axles as required to stop all wheel slip. When the front and rear output shafts rotations return to the same speed rotation, the shift control module sends pulse width modulation signals to the encoder/motor to position the transfer case back into rear wheel drive.
When the transfer case is engaged into four wheel drive, a lamp indicator on the instrument cluster will light. The automatic transfer case system is completely automated, no transfer case control button switching system is required.

Do you know what diagnostic trouble code's are ?

DTC C0300 Rear Speed Sensor Malfunction
DTC C0305 Front Speed Sensor Malfunction
DTC C0308 Motor A/B Circuit Low
DTC C0309 Motor A/B Circuit High
DTC C0310 Motor A/B Circuit Open
DTC C0315 Motor Ground Circuit Open
DTC C0374 General System Malfunction
DTC C0376 Front/Rear Shaft Speed Mismatch
DTC C0550 ECU Malfunction
DTC C0611 VIN Information Error
DTC C0895 Device Voltage Malfunction

Not OBD2 engine code's .

did you turn the locks on the wheels, or check the fuses

Which do you have ?
Transfer Case - NVG 236 (Two Speed Automatic)
Transfer Case - NVG 233-NP1 (Two Speed Selectable)
The NV236 transfer case is an automatic transfer case with three drive ranges. Shifting from rear wheel drive to four wheel drive is done automatically when the transfer case shift control module receives wheel rotating slip information from the speed sensors. The transfer case shift control module then engages the transfer case motor/encoder to position the transfer case from rear to four wheel drive. When the transfer case shift control module receives information that the wheel rotation is the same on both axles, the transfer case shift control module sends position information to the motor/encoder to put the transfer case back into rear wheel drive. The three drive ranges are 2HI, 4HI, and 4LO. The 2HI position is for normal driving with the rear wheels pushing the vehicle. The 4HI, position is for driving through sand, snow, mud, gravel, or heavy rain at normal or slightly below normal speeds. The 4HI engages the front axle to allow for four wheel drive. The front axle is pulling the vehicle, and the rear axle is pushing the vehicle. The 4LO range is used for off road driving, heavy snow, deep mud, or shallow fording. The 4LO is similar to the 4HI except that the gearing in the transfer case is set for low speed and high torque. The NV236 is manufactured at Syracuse New York by New Venture Gear a division of New Process Gear for General Motors.
Is the switch light on or flashing ? If you have automatic 4x4 there are several DTC'S that can set >
DTC B2725 ATC Mode Switch Circuit Malfunction DTC C0300 Rear Speed Sensor Malfunction DTC C0305 Front Speed Sensor Malfunction DTC C0308 Motor A/B Circuit Low DTC C0309 Motor A/B Circuit High DTC C0310 Motor A/B Circuit Open DTC C0315 Motor Ground Circuit Open DTC C0323 T-Case Lock Circuit Low DTC C0324 T-Case Lock Circuit High DTC C0327 Encoder Circuit Malfunction DTC C0362 4LO Discrete Output Circuit High DTC C0367 Front Axle Control Circuit High DTC C0374 General System Malfunction DTC C0376 Front/Rear Shaft Speed Mismatch DTC C0387 Unable to Perform Shift DTC C0550 ECU Malfunction DTC C0611 VIN Information Error

Is this a auto or Manual I ask as you say flywheel and all gears. tall us a little more. what is the gearbox ?. have you looked at the oil level and under it at the rear tail shaft, crosses. in 2 wheel drive and running can you get it into park. DON'T try to hard at this as it can damage the auto. If you can drive in 4 wheel low in all gears then it sounds like you may have a problem in the drive line. Tall us more

Go to a place that has a good smooth parking lot and a wooden private fence. Open all your windows and drive the car slowly as close as possible along the fence in order to pin point where the sound is coming from. The sound will echo back from the fence and will make it easier to pin point the area where the womp womp sound is coming from. Next thing you can do is lift the car up and place it on four jack stands in case you have a front wheel drive. If you have a front wheel drive and your car is on four jack stands, place you gear in nuetral and spin each rear tire separately to see which one is making the noise. Keep in mind that it might be a wheel bearing or if it a rear wheel drive and on four jack stands have someone drive it slowly while you listen for the noise. Some rear wheel drive differentials can make this noise if it is low on differial oil. Be very careful that the jack stands are on solid and making good contact with the car frame and flat on the pavement. Don't place yourself where the car can fall and hit you or run in to you. Good luck.

The basic explanation of these gears are as follows.
2up/2wd is a basic two wheel drive setting where the vehicle will react as a rear wheel drive. In this gear the transmission will only distribute power to the two rear wheels(best for all around driving with clear road conditions and will give the best fuel efficiency).
4up/4wd is a high speed four wheel drive setting. in this gear the transmission will always distribute power to all four wheels and will allow you to drive at higher rates of speed( good for poor road conditions when ice and wet roads are a moderate risk).
4dwn/4lo is a low gear four wheel drive setting where again the transmission will distribute power to all four wheels but will limit you to a low rate of speed(good for really rough roads and severe weather or very poor traction conditions).
auto gear selection is basically a all wheel drive setting, where the transmission will use a primary setting of rear wheel drive gearing until the vehicle slips or looses traction on one of the drive traction. as soon as the transmission detects a difference in wheel speed between the two rear wheels, at which time the transmission locks up the front differential turning itself into a four wheel drive, until the wheels have regained traction and remain spinning at the same speed for a set amount of time, at which time it will then unlock the front differential at return to a rear wheel drive setting. this is a good all around gear but will cause you to get slightly less mpg/kpg then a 2up/2wd gear would. i hope this helps

If you have an actuator box on the passenger front axle that may be disconnected or broken. If not remove the cover from the front differential and check the gears...they may be broken.

You have to have your front hubs locked in for four-wheel drive to work

Based on another similar problem and it was fixed driving backwards, that's exactly what I did. I drove the Rodeo backwards and then would stop and put it in gear and did this for 10 minutes until I worked the 4x4 gear loose and now all four wheels run. I must say, I created quite a sight driving backwards in a Wal-Green's parking lot for 10 minutes.

first off your heater dial swithc is buggered. and as for the four wheel drive is it all electric diff locks or do you have to get out and lock hubs in etc?