i have 93 f250 351eng and E40d transmission...... With the snow i have the lock outs in four wheel ( manual lockouts) when going from two wheel to four wheel no problems but sometimes going from four wheel drive to two wheel drive i get a vibration like its not coming out of four wheel drive it feels like a ujoint vibration but other times there is no issues any ideas?

 

When going out of 4wd to 2wd you still have extra parts turning if the hubs are still locked, so there WILL be extra vibrations. Sometimes not noticable sometimes bad.
Unlock the hubs.

 

Only when shifting, then smooth? Are you shifting under power - should coasting, no load on the drivetrain.

 

Also it might not be coming out of 4WD those times. I know the transfer case in my '97 shifts WAY too easily. It never binds and won't let me move the lever. So I strongly suspect that the lever isn't solidly connected to the shift fork, and that it's just loading a spring so the case will shift once it's not bound up.

If that's really what happens it might sometimes shift into 2WD right away, but other times might stay in 4WD for a while.

 

That is what i think is happening because if i get back on something slick the vibration quits..... How hard is a transfer case to rebuild? Thats one of the few things i have nvr done.