I've got some droning from my front diff, suspect the pinion bearing. It is a 2007 SE with about 130k miles. Most if the threads I've read have been older - is the current thinking to buy a refurbished diff and replace vs doing a rebuild? Any guidance on suppliers good v bad?

I've also wondered whether it can be swapped with a low mileage LR4 front diff. I understand LR changed from the steel ones that had problems to alu for the LR4 and that they last longer - are they a straight swap or even possible?