We have recently discovered a problem with the front drive shaft of my wife's 2005 Range Rover. It appears as though the splines on the end of the front drive shaft or prop shaft (part that inserts into the coupling) has worn down. The problem is that I can replace the drive shaft but the drive shaft coupling is impossible to find. I called my local range rover and was told the coupling is a part of the differential. I'm a novice (less than a novice) and need help understanding. I have looked up the front differential and cant see where the couple comes is a part of the front differential. Can I buy the coupling separate and if so where can I buy it from? If not what are my options? I appreciate all the help I can get.