2005 Chevrolet Impala • 150,000 miles

My wife was using the wipers when the drivers side wiper just went off the windshield to the left. When I got to her to check on it the wiper arm was very loose and you could move it in any direction with your hand. The arm seemed to be broken or a nut or bolt loose. The passenger side arm seems to be working fine. Any suggestions would be great. Thanks!
October 9, 2011.

Lift the arm up and where the arm hooks up youll see a little clip. Pray it out and you can remove the arm. Then turn on the wipers on and watch the round piece. You should see it moving back and forth. If no check the wiper transmittion for being broken. Almost always the wiper arm gets striped and needs replacement.

Oct 9, 2011.
The nust that holds the wiper arm to the splined shaft gor the motor has come loose.
Below are the instructions on how to install it. Also there is a diagram on what it looks like if taken apart.
The most important thing to remeber in the instructions is to pay attention to lining everythin up when you tighten it or the wiper will hit the windlshield edge.