I was driving my 07 650 h1 when suddenly the front diff started clicking. I was in 2wd. The clicking only occurs when in 2wd. When in 4wd it is fine. And it engages into 4wd fine. I jacked it up to locate the problem and it is definitely in the front diff. While jacked up I will spin the left and right front tires and the clicking will occur. It feels like something is in between engaging. The click barely grabs some kind of gears within the diff and when jacked up. the click resembles the sound and feeling of putting a tractor in gear with no clutch at low rpm. If anyone has experienced this or has knowledge of what could be happening please let me know. I was wondering if there is a way to fix this without splitting the diff. Thanks a bunch and enjoy no dust this time of year!!!