Getting no power to the front wheels. Replaced the encoder because it seemed like the easiest place to throw money. Took it to a shop and found no stored codes. They said the prop shaft coming from the transfer case was turning but not the front wheels. Jacked it up at home and both wheels will free wheel without turning the opposite wheel or the shaft. Turning the prop shaft does transmit rotation to the wheels either.Is my differential toast?

Is your diff toast? Probably not unless someone activated 4hi while the rear wheels were spinning.

More than likely, you have suffered a vacuum actuator failure or transfer case switch is sticking closed.

If your good with some common tools follow this video to diagnose it...

Thanks for the reply Mike.I am familiar with that from my old Blazer, but the Bravada uses an encoder on the transfer case. I am most concerned about the freewheeling from side to side and nothing even when turning the drive shaft by hand. From what I have been able to find, when on jackstands, I should be able to turn a wheel and have the opposite wheel turn the other way. I get nothing.

I thought the encoder was for 4hi and 4lo and tells the BCM what mode its in.

Not sure on the actuation of the diff itself. I guess one way to tell if its working would be to is remove the vacuum actuator, and actuate the cable manually and semi-permanently fix it so the front diff is engaged. Then rotate the input shaft and see what happens or one of the front wheels.

The encoder motor locks the front driveshaft in and out. Doesn't have the actuator and cable setup.

Oh wait, Bravada'* are AWD and not 4x4 correct?

Yeah....I'm thinking either the splines are shot on the axles or the spiders are torn up.

Yea, sounds like its time to rip it out and check it out.