did you use the nut to draw the axle into the hub? that is a big no no on these

 

I had it pushed in as far as I could but as I was tightening the nut it was most definitely drawing it tighter. I did hear something pop as I was tightening the nut but just chalked it up as something seating.

 

You must either pull a vacuum on the IWE to pull it to the disengaged position, or align the teeth as you slowly titghen the nut. Here's a good video on replacing the IWE without using vacuum, same way I do it. It sounds like you busted your brand new IWE.
I "assume" you have a Ford truck, no idea what year or trim level, you need to give us a clue as to what you're driving.

 

Like I said in my second reply, time to check the condition of the IWE(s) that gave you that popping noise.