I recently brought my 2014 XV Crosstrek with 171K miles into the dealership to have it serviced (oil change, F&R diff service, R&B wheels, etc.). During the service it was brought to my attention that a crack had developed in my front differential (specifically the Differential Overflow Plug) and that I had to buy new transmission for $9000 as the CVT and front differential are part of one assembly that can only be replaced together. Given the location of the damage, I feel like the service department should own the cost of the replacement as the differential was fine prior to servicing, but they are maintaining that the damage is not their fault. They put some epoxy around the crack to reduce the leaking fluid from the differential while I figure out what to do.
Some additional information: I had my CVT serviced in August of 2019 and no damage was observed to the front differential as part of the final inspection. So I know it was fine then and it has only been worked on at that location.
My Question here is: Does anyone have any experience with a differential cracking through normal driving? Is this something that “can just happen” or is this the result of negligent servicing? Am I way off-base with my request that they cover the entire cost of repair?