I assume those coils are just overload springs of some sort. Until I zoomed in I couldn't see the leaf springs. Coils only would indicate 72 and prior truck but I'm not sure if they were even available on 4x4 then.
I just had the exact same issue. I ended up replacing the module again along with the coil, cap and rotor. Problem solved but I'm not sure what fixed it.
The problem with most of this stuff is you don't figure out it's wrong until you get it and it's easier to make it work than send it back and continue the search.