The dana 80 rear in my dually is no longer a locking rear, I am sure with the miles the clutches are worn out. I tried changing the oil and put no additive in but this did not help. Can someone tell me the best place to buy a clutch pack for this rear would be? I found them at quad 4x4 but at $200 it seemed a little pricey but maybe that is the best you can do.