wheel hubs staying locked

[keith1000]

Hi all

I have a 04 f350 crew 4x4 (lock/auto wheel hub). The other week I felt a weird knocking/hopping feeling like driving in 4x4 on dry pavement, but was not in 4x4. So I lifted the front end and turned the wheels and noticed the axle/front drive shaft still turning in 2 wheel drive (also noticed very bad milage since the last time I used 4x4). So I took it to a local garage and he told me my wheel hubs were siezed, and its 300 bucks a side to fix. Well I drove the truck home pulled the hubs off and it was all good inside the hub, lubed and free, only thing that seemed seized was the actual turn knob (outside of hub), so I took the hub apart got the dial moving and put it back together (both sides) and off I went, both wheels were unlocked from the axle, so to test it I drove 4x4 on the fly, stopped, neutrel, put it back in 2 wheel, it worked fine, both wheels unlocked free from the axle. Well yesterday I had to use 4x4 again, and this time around with multiple attemps to unlock, the wheels are still locked to the axle.
I am new to the auto lock hub, all older 4x4s I had were manual locking hubs, can someone please explain to me how the auto hubs work? am I in the market for new hubs, or is there something else that may be causing this?
please any info will help
thx Keith

[bigbear75]

Keith1000,

on my 2000 psd it did that same thing and it turned out to be the rubber boot part of the auto lock system that had a few pin holes in it. The auto lock works on a vaccuum system (So I'm told by my local garage guy) Now here i am with my 05PSD6LCC with 46K miles now makes a suttle clunking feel in the floor board but can't hear it...when turning almost full turn (Notice more on left turn then right) in 4x or 2 wheel drive. Sorry i wasnt a big help but at least gave you another thing to check out.