whining sound coming from rear of car

What is your question?

My 2005 4.0 pony has 165,000 miles on it. I recently had a seal on the right rear start leaking and had them both replaced. Now, about 2 months later, the rear end has started a whining noise. when I am coasting there is no noise, only under acceleration. Could it be the wheel bearings making the noise or is it more likely to be the differential? Thanks!