4x4 not disengaging????

[pjreil]

I have a 91 explorer xlt and just recently it has started making clunking noises in the front end when it is in 2 wheel drive only...If I put it in 4 wd it doesn't do it... It doesn't happen all the time but is happening more often. It seems to happen when I am turning a corner. It almost sounds as if it is not quite disengaged, almost sounds as if a front u joint is out of it, but they seem ok..It is a major clunk, clunk clunk and if I stop and back up it stops, that is why I am thinking it is a 4x4 problem. Anyone have any ideas??? It is the push button 4x4

Thanks

 

[JStrider]

what 4x4 system do you have? is it the push button one...

do you have automatic or manual hubs?

maybe the hubs didnt unlock properly? the auto hubs are a common fail point...