For those of us who like mysteries

I recently bought a 2007 silverado 1500 Z71. About a mounth after we took ownership we started getting premature engagement of the antilock brakes and pulsating breakes, this was on dry pavement.
With the 4WD in auto, it seemed as if it would go in 4WD, even on dry pavement. I took it to the dealer and they replaced a wheel speed sensor. About a week after the sensor was replaced I noticed that if you take a sharp turn, wheels hard over, you would get a heavy wine from the drive train. Last week the misses was at the grocery store and leaned in across the driver seat to start the truck and she said the truck jumped forward, kinda like starting a standard in gear, except not as dramatic I guess. When she put it in gear, there was a huge clunk, she says "like the motor dropped out on the pavement", but it drone fine. The service 4WD light was on  couple  and the wining was there for a few days, then it just stopped, the 4WD light is now off. Has anyone ever had anything close to this happen to them. I am out of town on a job for another week, so I am not able to check the truck out myself.
Thanks in advance
Clyde