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2006 chevy trailblazer_ls
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Discussion Starter #1
i bought my 06 trailblazer for 3k with 40k miles on it.... it was a steal it kinda just fell into my lap. it is however only 2wd. I just did the math on what i would need for a 4wd conversion transfer case with shift motor front diff two cv axles and two new drive shafts is only 239 at my local junkyard (dont ask me why theyre selling a transfer case for 70 bucks). I don't care about awd.

Mechanically is that all i would need. Do the 2wd hubs already have the spline for the cv axles? do i need a new oil pan for front diff clearance?

next the reason everyone says its impossible the electrical wiring can you mechanically turn the spindle going into the encoder motor to switch it into 4wd high and low because i have no problem crawling under my car to engage it when i want to go offroad. Does anyone know what i need to engage to actually make the wheels turn does the clutch engage separately from the high and low gears

lastly if there is anything im not thinking of through my rose colored glasses let me know because im going to the junkyard this weekend to buy a transfer case and wiring harness for it to see if i can physically get it to shift to 4wd before i buy everything else
 

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The Auto 4WD position allows the capability of an active transfer case, which provides the benefits of on-demand torque biasing wet clutch and easy vehicle tuning through software calibrations. The software calibrations show more features such as flexible adapt ready position and clutch preload torque levels. The technology allows for vehicle speed dependent clutch torque levels to enhance the performance of the system. For example, the system is calibrated to provide 0-5 lb ft of clutch torque during low speed, low engine torque operation, and predetermined higher torque for 20mph and greater. This prevents crow-hop and binding at low speeds and provides higher torque biases at higher vehicle speeds, to enhance stability.



The NVG 226 requires no clutch shimming. the transfer case control module controls for the wear of the clutch and different clutch torque levels. The software learns adapt ready positions, which are for the correct clutch torque. The learned adapt ready positions vary as the unit wears over its life.

When the NVG 226 is in the 2 HI mode, the power flows from the transmission to the input shaft gear (1). The input shaft gear is connected to the rear output shaft (5) by the high/low range collar (2). The range collar inner teeth, high speed, are engaged with the input shaft gear (1) high speed position teeth. At the same time the range collar is slip splined to the rear output shaft (5). The rear output shaft delivers the power flow to the rear propshaft (6). The position of the control actuator lever shaft (8) allows no clutch engagement. The shift detent lever (7), which moves the shift rail and shift fork (10), is in the high speed position on the control actuator shaft (8).

In the 4 HI mode, the power flow to the rear propshaft is the same as in the 2 HI mode. To deliver power flow to the front propshaft during the 4 HI position, the transfer control module commands the encoder motor to apply the clutch to a calibrated torque. the encoder motor turns the control actuator lever shaft (8). A brake in the encoder motor holds the control actuator shaft in the full clutch position. The control actuator lever shaft (8) is cam designed and the cam action moves the clutch lever (4). The clutch lever (4) pivots on the control lever picot studs and moves towards the clutch apply plate, to engage the clutch. As more pressure is applied to the clutch apply plate, the clutch disks are compressed. Using inner clutch disks, which are engaged with the clutch hub (3), and the outer clutch disks, which are engaged with the clutch housing, the power flow is delivered to the clutch housing.

The clutch hub (3) is splined to the rear output shaft (5), and the clutch housing rotates on a needle bearing on the rear output shaft (5). The chain drive sprocket is splined to the clutch housing. The power flows from the drive sprocket, through the chain, to the chain driven sprocket. The driven sprocket is splined to the front output shaft (9). The power flow is delivered to the front propshaft through the front output shaft (9).

During the Auto 4WD mode, the power flow is the same as it is in the 4 HI mode. Except during the A4WD mode, the encoder motor rotates the control actuator shaft lever to the learned adapt ready positions. Rotating the control actuator to the carious positions changes the clutch torque level. When a differential of front propshaft and rear propshaft speed is recognized, the transfer case control modules commands for more, or less clutch torque.

When shifting the transfer case to the 4 LO mode, it commands the encoder motor to turn the control actuator lever shaft (8) to move the shift detent lever (7), and to apply the clutch. The shift detent lever (7) moves the shift rail and the spring dampened shift fork (10). The shift fork (10) moves the high/low range collar (2) on the rear output shaft (5) splines toward the rear of the transfer case. The range collar (2) inner teeth, high speed, disengage from the input shaft gear (1) high speed teeth. The range collar (2) outer teeth, low speed, then engage in the planetary carrier teeth. The power flow is now from the input shaft (1) planetary teeth to the planetary gears in the carrier. Rotating the planetary gears, which are engaged in the annulus gear, the carrier rotates. The carrier, that is engaged to the range collar, then drives the rear output shaft. Therefore, providing a 2.69:1 reduction to the speed of the rear output shaft. The power flow to the front propshaft is the same as it is in the 4 HI mode.

A neutral position is obtained when the range collar is not engaged to the input shaft gear or the planetary carrier. Neutral position is used for towing the vehicle.



some useful information the clutch and gearing are driven at the same time with the spindle and from what i can understand moving the spindle both switches the gears and the amount of pressure to the clutch... so im thinking the only way to do this would be to make my own micro controller to control the pwm signal to the encoder motor (im a failed engineering student but ive used stepper motors before and messed around with cheap micro controller boards... figuring out electrical control will be difficult but in the scope of my capabilities)



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 (drivers side) of the transfer case. When activated it turns the sector shaft of the transfer case (clockwise or counter clockwise) 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 to allow the motor to shift the transfer case from 2HI or 4HI to NEUTRAL and 4LO positions.
 

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Discussion Starter #3
more random information about trailblazer transfer cases

New Venture Gear transmissions and transfer cases
The Muncie, Indiana, plant under New Venture Gear produced the NV4500, NV3500, and NV3550 light truck transmissions.
The Syracuse New Process Gear plant produced transfer cases for all of the "Big Three" Ford, Chrysler, and General Motors. The NV 247 all-wheel drive transfer case, sold by Chrysler's Jeep division as the "Quadra-Trac II", the

manual transaxle for the Dodge Neon and PT Cruiser (T-350), and manual transaxles for European export Chrysler minivans (T-650 & 750) were the bulk of their last years of production.
Transfer case model nomenclature

Manufacturer Number of speeds/gears Strength Type
NP = New Process Gear
NV = New Venture Gear
1 = One speed (high range)
2 = Two speed (high and low range)
1 (low) to 7 (high)

1 = Part-time 4WD
2 = Full-time 4WD
3 = Electronic shift
4 = Not currently used
5 = Torsen-type differential
6 = Computer controlled multi-plate wet clutch
7 = GeroDisc
8 = Not currently used
9 = Viscous coupling
Source: Sankar K. Mohan of New Venture Gear
 
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