4x4 makes clunking noise when engaged

[AHPPinstripes]

I have a 1994 Explorer Sport and when i went to engage the 4wd the light came on then as i tried to get out of the sand there woudl be a loud clunking noise coming front it seemed the front end area. Also it didnt look like all 4 wheels where turning. Im not sure what the problem is. If any can help please do so. THanks

 

[mikeinri]

Do a search on this site for the following. Remove/clean/reinstall your auto hubs and spring cams. After that, inspect (and potentially replace) your u-joints.

Mike

 

[DeRocha]

As Mike has indicated, HUBs and U-joints are the most common. When were the hubs last inspected/serviced? How old are the U-joints? Is there enough fluid in the front diff? Where exactly does the noise come from (driver, center, or passenger side)?

BTW you most likely have open differentials which will only power 1 wheel in the front and 1 wheel in the back. The wheels getting power are the ones with least resistance...