Really need more info here. Is it the same carrier? If you are just replacing bearings it is recommended to check gear tooth pattern and backlash before the teardown. Then again when you are done. They should be close to the same. And hopefully not too far out of spec. If you change it too much your gears could make some noise.
The last one I did, I put new bearings in a power-lock rear. The back lash before was .016 and .011 after... I think, it's been a while. I think spec is .006 to .009??? Anyway I went closer to spec and it works fine, no noise at all.