Not bustin’ balls, but you don’t “hear” dogboxes as such. You can hear straight- cut gears (whining), but dogboxes don’t neccessarily have straight- cut gears-- most do, but not all. Dogrings can be installed on helical cut gears, and those trannies are quiet.
Last I heard Shep doesn’t run welded diffs. I believe he did have a welded center diff early on, but no longer. If I had to guess I’d say he’s running spools.