I just took my brother's truck apart same issue u had but for the life of me couldn't get how they would replace the tone ring so I didn't change it nor did I bother trying I thought it was part of the crankshaft and figured I was better off leaving it alone . Did they tell u how the tone ring...
So I've been working on my step brothers truck I'm no diesel mech but I am pretty handy with my tools .so he was driving and all of a sudden everything shut down wouldn't start so he gets towed home well then I scanned his truck it's a 2015 ecodiesal 3.0 and I get 4 codes one was the crank...