My factory rear axle breather failed but I was fortunate that it only blew out my rear diff cover seal.
What do you mean,, when you say it failed?
It's just a simple threaded short metal Hollow Pipe, with a crimped metal cap over the top, that allow's for Fluid Expansion. The Breather need's to be checked from time to time. The Frontier is not designed to go through Deep water or mud, that might stop the Breather up, or containminate the Axle Oil.
I do have an issue with Nissan not includeing, checking and cleaning the Axle Vent.
I had a '93 hardbody for 20 year's,, and never had an issue with the axle vent stopping up,, but I did check the vent from time to time or at least, when I changed the Axle Oil. When I check the axle vent,, I take it out,, and clean it with diesel fuel,, then blow it out with the air compressor.
In the Cold Country where haveing to drive the Truck in Snow, etc,, I can see that the Vent might get clogged up,, and would need to be checked more often. Or driveing on Dirt/Gravel Road's,, I can also see that the vent could get clogged up by Dust and Dirt, and need to be checked more aften.
I haven't needed to do the Axle Vent Mod,, so I can't advise there, but the Mod, will need to be checked from time to time as well, to make sure the vent is free flowing.