[blazee]

It sounds like your front differential is partially engaging. The most common cause is the vacuum switch on the transfer case. This vacuum switch controls the vacuum to an actuator located under the battery tray. The actuator controls a cable that goes to the front end to engage and disengage the front diff. When the switch goes out it won't let the actuator work properly, you may even notice tranny fluid in your vacuum ball and/or A/C contol vacuum lines. The switch is less than $20, but you should also inspect the vacuum lines, actuator, and cable for proper operation.

If you go too long without fixing it, you can destroy the gears in your front end which would be a very expensive repair.