[mickmate]

Have someone wiggle it for you while you look underneath. I just replaced inner stub axle bearings in a Jag diff that did that. The new bearings are sealed cartridge style and very nice. That's likely what ERA uses but it would be nice to see where it is coming from as it might be all from one place. I don't think it's unusual between inner and outer axles and inner and outer u-joints to have a stack up of tolerances resulting in what you are feeling. The half shafts are the upper arms in the suspension so you don't want to see, feel or hear excessive play. They do a pretty good job of letting you know when they are ready to be changed.