Ok, So, Im 40 miles from home stuck in ice and snow in a hotel.. (my wife works close by- thought it would be safer than driving in the 10 inches of snow we got 3 days in a row) so, I go to pick her up tonight and I engage 4hi.. I hear the click and the light comes on.. but no clunk of the hubs locking.. I drop it in 4 lo.. it shifts in low.. but the hubs are not locking..

I hear a ticking sound as I drive and when I put it in 2wd it goes away.

I turn off the truck, turn the wheel hard both ways .. get out and I can physically turn the drive shaft and I hear the ticking in the hubs. If I read correctly when the truck is off these should be locked?

is it possible the vacuum is not releasing?

I also get the groaning when I start up of the air diverter.. that im told is operated by vacuum.. so I am guessing I have a vacuum problem??

please advise! I want to get home.. and Arkansas doesnt know how to care for the roads!

Thanks!