There is no 'diff. oil recall' on an MDX. The VTM4 fluid should have been changed at 7,500 and then again at 30,000 miles. I have seen 2 MDX's with noisey diffs because the fluid was changed with something other than Honda VTM4 fluid, and 3 or 4 that were niosey because they had never been changed. I have never seen a diff problem in an MDX that was properly maintained.

Change the diff fluid and hope that there is no permanent damage.