Scraping noise in 4WD

Ok i have an odd scraping noise from my transfer case area that only happens while decelerating in 4wd with d 18 engaged. doesnt do it with the fronts locked in and the 18 not in 4wd. doesnt do it with the front not locked in and the 18 engaged, which leads me to believe its a front axle prob. my front drive shaft is terribly loose and to short to boot. my front axle knuckle goes out and in if you turn it back and forth by hand, but the change is absorbed by the drive shaft. anybody have a good 27 with 3.73's or maybe just the innards?

Shafe

 

Have you checked to see if the front drive shaft may be rubbing the skid plate? I've seen it happen on some jeeps when the front drive shaft is worn.

 

skid plate is off

 

Dry surface? Wet surface? Slippery surface?
Under what conditions does it do it? You say with the hubs locked in and the transfer case unlocked no noise, so while not eliminating a front axle issue certainly leads in other directions. What kind of shape is the slip joint on the front drive shaft?
Have you checked the body to transmission clearance and motor and transmission/transfer case mounts? Load on the drive train can cause it to lift and hit the body, especially under deceleration.

 

is it rubbing on your starter by chance. are your leaf springs weak?

 

All surfaces. slip joint is very very bad and DS is to short to boot.