I have a '96 Blazer 4.3L with 4x4. Recently with the increase of snow in MI I have been using my 4x4 more. I have noticed that 4LO is no longer working properly. 2HI & 4HI both work without a problem. It shifts into 4LO without a problem but once you start moving there is a problem. It will only go a short distance (50ft or less) before it starts clicking/grinding noise occurs. As soon as this started I have stopped using 4LO. I have no idea as to what the problem is as this is my first 4x4. Any guidance is much appreciated.