Transfer Case Question
 

This is how i understand the trans case to work in an AWD.

When you put the vehicle into 4hi, 4lo or AWD (labeled 4x4 on mine) the electronic shift motors sensor responds by engaging a specific plate for hi, lo or 4x4. The rotary cam in the shift motor moves a fork to the corresponding location. It then uses manifold vacuum to lock the hubs and transfer case together. (is this correct?)

If that's the case and your transfer case will not shift into the correct setting a couple of minor things could be wrong. Assuming that a different vacuum line is used for 4hi 4lo than for 4x4/AWD you could have a leaky line or the fork could be bent for just one setting? Also, could it just be the linkage since 4x4/AWD is mainly what's used?

I'm hoping a pro in here will know the answer to this. Thanks in advance!

do you have an electronic shift dial or a lever out of the floor for your 4x4 selector? i do not believe there is any vacuume involved. but i have been wrong before. on the AWD's there is a differential in the tcase that distibutes the power to the front and rear diffs. when you shift into 4hi or lo it locks the diff in the tcase and gives equal power to the front and rear wheels. thus is why so hard to turn on dry pavement when in 4hi or lo. i have open diffs in both the front and rear, not lsd. so even in 4hi-lo, i only have 1 wheel in the front and 1 in the back doing the work.

What year is your Dakota?

At least in this generation Dakota there is no vacuum involved. It's either mechanical, up to 2000, or electronic, 2001+. Yes, shift forks can bend but more commonly the its a mechanical problem with the shift motor.

The hubs do not lock/unlock. They are not equipped to do so. The front drivetrain rotates as long as the vehicle is moving, you can not disconnect the hubs.

Like McNasy says, there is a differential type unit in the AWD transfer case that controls torque between front/rear. When you select 4x4 lock, this unit is locked together.

I know there is a gear in the tcase called the viscous gear that allows power to be transferred where needed.

So no vacuum, so if it won't shift into 4x4/AWD I could either have a bent fork or a motor issue then. I don't wanna rebuild the transfer case if I don't have to. I assumed if it was a motor issue it wouldn't work at all, it just wouldn't shift into any of them, is that right?

If it wont shift into any of them then its prob a motor issue. Normally if the motor isnt working the light on the 4wd switch will start flashing.

It'll shift into all them except one. I know with transmissions you can lose a gear and it'll work, but expect it to take a dump soon. Wasn't sure if transfer cases were the same way.

Also could it be the shift motor sensor is defective in some way?

There is no viscous drive in the transfer case. It is a geared differential.

What year is your Dakota?

What mode won't it shift into? What does it do when you try? There are reasons it may not shift into some modes, just during normal operation. If there is a load on the driveline for example.

2000 AWD or All the time 4wd. It'll shift into 4hi and 4lo. Won't shift into 4x4/AWD.

Go to the Dodge/Chrysler website. Punch in your VIN number. See if there was a recall on that transfer case. I know my 2001 had one and I got mine replaced for free. And I was the second owner. Pretty sure I had it done in 2007. They still honored the recall years later.

All right. It's a mechanical linkage in 2000, no motor or electronics to deal with.

If there is any binding in the drivetrain, you may not be able to shift it. Are you moving when you're trying this? If so, back off the gas for a second as you shift.