I sent one of my SD70 ACe Diesels out there for repair. They received it on May 15, 2017.
I haven't heard anything yet. I guess all the repair shops are back-logged,
I also sent back a Santa Fe F-3 back to MTH in Columbia, MD. for under warranty repair. They received it on June 9, 2017. Heard nothing yet.
You are better off repairing your own engines yourself if you can.
I can repair my old engines myself, but don't know much about the new hi-tech engines and diesels out there.
Ernie