I have a 2003 Explorer EB that on deceleration of all speeds, the drivers side rear axle is popping or clicking . Could this be a CV joint ? It does not happen on acceleration.

 

Does this noise happen when coasting or only when the brake pedal is being depressed? It's not likely to be a CV joint or transfer case (assuming 4WD or AWD) if it does not make noise on acceleration/under load.

-Rod

 

Its a AWD... It only occurs under braking and coasting. When no load is on the drive-train. I took the wheels off and it seems to have a little play "1/4 inch or so when I turn the rotor by hand.

 

The 1/4 inch of play, is that rotational movement or in and out movement? If rotational, then that doesn't sound like an issue. If that's in and out, then it sounds like you either have wheel bearing issues or an axle shaft nut that is loose.

Since the noise only is present under braking and coasting, I'd suggest a careful inspection of the brakes followed by the suspension components, and if there's still nothing obvious, drain the rear differential fluid and look for signs of metal.

-Rod