2003 Chevy Suburban Z71 - 4WD Problem

[mn2ga]

I have a 2003 Chevrolet Suburban Z71 with less than 50K miles. It has been over a year since I used the 4WD. However, I went to use the 4WD (high mode) today and it 1)felt as if the emergency brake was on because it would hardly move forward, 2) made a very loud "moaning" noise and vibration through the undercarriage when it finally started to move and 3) made a "clunking" noise (like the drivetrain was literally dropping) when I changed it back to 2WD.

I did not drive it more than 50 feet, for fear it was causing damage. Any suggestions?

Thanks!

[J-Ri]

Might "just" be some parts have rusted from not being used for so long. Take a look at the diff. and T-case lubricant.