My 4WD (4 wheel drive) is not working why?

The brain for the 4x4 is the TIPM which they had problem with. If the wiring switch and motor are all okay it only leaves one thing it can be, the TIPM

No problem please let me know what happens :)

Have you tried the standard backing up? If you have, then check to see if there is power to the actuator on the transfer case. If so the actuator is bad here is a diagrams below to help fix it.

Hi,

If there are no odd sounds, chances are the linkage is either failing or needs adjusted. There is a shift rod between the lever in the truck and the transfer case. There is an adjustment on it. I've seen them come loose, rust, and even break. If you look at pic 1 below, I circled the part I'm referring to.

Here are the directions for adjustment. Start with this. Also, the same picture correlates with these directions.

ADJUSTMENT - SHIFT LEVER
1. Move shift lever into 2H position.
2. Raise vehicle.
3. Loosen shift rod lock bolt at trunnion.
4. Check shift rod fit in trunnion. Be sure rod does not bind in trunnion. Lubricate the shift rod and trunnion if necessary.
5. Verify that transfer case shift lever is in 2H detent position. The 2H detent position on the transfer case shift arm is the second position from full forward.

6. Align the adjustment locating hole on the lower shifter lever with the adjustment channel on the shifter bracket assembly (Fig. 90).
7. Insert an appropriately sized pin through into the adjustment channel and through the locating hole to hold the shifter in the correct position.
8. Tighten shift rod lock bolt to 10 Nm (90 inch lbs.) Torque.
9. Remove the locating pin from the adjustment channel and locating hole.
10. Check shift linkage operation. Be sure transfer case shifts into and operates properly in all ranges.

Check out the diagrams (Below). Please let us know what happens.

Check to make sure your shifter is working and has proper adjustment. There is a locking bolt on the linkage that may have fallen off. It sounds like the actuator may have gotten unplugged during the repair.

The locking bolt is near the end of the rod. You will have to have a helpermove the shift lever to see if it's working. If the rod is working then there is something wrong inside the t-case.
ADJUSTMENT � SHIFT� LEVER

1. Move� shift� lever� into� 2H� position.
2. Raise� vehicle.

Fig.� 118:� Shifter� Adjustment
Courtesy� of� DAIMLERCHRYSLER� CORP.

3. Loosen� shift� rod� lock� bolt� at� trunnion� (Fig.� 119).

Fig.� 119:� Shift� Rod� Lock� Bolt� Location
Courtesy� of� DAIMLERCHRYSLER� CORP.

4. Check� shift� rod� fit� in� trunnion.� Be� sure� rod� does� not� bind� in� trunnion.� Lubricate� the� shift� rod� and� trunnion� if� necessary.
5. Verify� that� transfer� case� shift� lever� is� in� 2H� detent� position.� The� 2H� detent� position� on� the� transfer� case� shift� arm� is� the� second� position� from� full� forward.
6. Align� the� adjustment� locating� hole� on� the� lower� shifter� lever� with� the� adjustment� channel� on� the� shifter� bracket� assembly� (Fig.� 120).

Fig.� 120:� Shifter� Adjustment� Location
Courtesy� of� DAIMLERCHRYSLER� CORP.

7. Insert� an� appropriately� sized� pin� through� into� the� adjustment� channel� and� through� the� locating� hole� to� hold� the� shifter� in� the� correct� position.
8. Tighten� shift� rod� lock� bolt� to� 10� N.M� (90� in.� Lbs.)� Torque.
9. Remove� the� locating� pin� from� the� adjustment� channel� and� locating� hole.
10. Check� shift� linkage� operation.� Be� sure� transfer� case� shifts� into� and� operates� properly� in� all� ranges.

Hazirka this should be reposted but if you have the diagram it's pretty self explanatory look at both pics in answer.

Hazarika, in the future you must repost or these questions won't be answered. The arrow in pic points to the way of tcase

Okay, so you have the rear drive shaft out, but are trying to drive the truck by putting it into four wheel drive and running power to the front axle correct?

You are seeing the front drive shaft spin but not getting any vehicle motion? That would not be the transmission. It would be an issue in the front axle. Most likely the center axle disconnect is not engaging. If the transfer case was out it would be easy to miss connecting all the vacuum lines that go to the selector switch that controls the CAD.