Not sure where to go on this at this point. Replaced passenger side CV shaft, it was binding and popping enough to see the axle housing deflect about an inch or so untill it would pop loose. After replacing the shaft, all worked good on the lift until I backed up in the driveway. As soon as I turned the wheel the problem was still there.

As of now I'm wondering if the 4x4 is not disengaging. I've never really messed with AWD much so am not sure where to go from here in troubleshooting. As far as I know only the normal 4x4 trucks use a vacume actuator on the front diff so I guess the selector motor at the transfer case would be a good start. Is there a way to manually disengage things to at least test.

I get a good growl and howl from the front end mostly when turning on dry pavement and a little when running straight down the road too.

I appreciate any feedback, it'd be awsome of someone has some additional online resources for me to research this further too. Sorry for the long first post... Truck is a 99 Expedition with 5.4 and Auto trans if it matters.

Thanks,
Matt