Noticed a whining noise between 16-22mph that just started during these cold (25-30 degree) mornings. It sounds like it may be coming from the differential or wheel area? About 65,000 miles. Anyone have any suggestions?

 

I was just going through the TSB's and came across this one. TSB 03-004-04 and under the symptoms/conditions it states that some vehicles may exhibit rear axle whine at speeds between 35 and 70mph. It states to replace the propeller shaft and it should take less than 1/2hr to do this.http://dodgeram.info/tsb/index.html

 

Thought that may have been the problem, but that TSB only applies to 4x2 models.