When playing a CD for a while, it starts to get static, then eventually goes out
I can shift from drive to neutral or park and it acts fine, then shift back to drive and get static again. Can't figure this one out. Please help

You don't mention if the static occurs when the truck is in motion vs stopped and parked. You may have a poor electrical connection if this occurs when driving. Check for radio fuse connection, back of radio/CD deck connector connection, deck electrical ground wire to chassis connection.
Good Luck.