Recently I've developed a whine in the drivetrain. I have a Shep trans with 3 & 4 gear from Evo 9 and stage 1 t-case. It only whines while decelerating in gear. Its only inbetween 20-45mph. Gets quieter as I slow down. Its not affected by RPM at all. I'm hoping its not death whine, but I'm not getting my hopes up. Anyone else run into the same issue? If so, what was the problem/solution?

 

I also have a deceleration whine, but I'm thinking its coming off the 12-plate rear diff.