I wonder if the shop you're using is old-school enough to know how to adjust Dana wheel bearings?
It's surprising (even though it shouldn't be anymore!) how many professional mechanics don't know the proper adjustment procedure, and some that don't even have the proper tools for these axles and simply adjust it "by feel" like they do so many 2wd trucks and passenger cars.
Definitely not the same procedure.
Might not hurt to ask, or watch how they do it when putting it all back together.
We've even had instances of members here having shops put their junk back together with the old hammer-and-chisel method.%)
Apparently that's what some mechanics thing those four notches in the adjusting nuts are for!
Paul