I have recently had a popping/grinding noise in the front end of my 2000 4x4. Installed a 4x4 posi lock as the front end kept kicking out of 4wd.The posi lock did not help.It does engage the sleeve in the axle completely.It still kicks in and out of 4wd.The axle u joints are good.Do these trucks have hubs.The noise comes from the front passenger side tire.If anyone has any ideas I am very much interested.