The SOAP trends on 'FCs failed gearbox were increasing rapidly prior to the accident. In fact some of the metals were well above BAH's internal alert levels. The gearbox remained in service as the levels being recorded were still below that recommended by Boeing in the MM.
Rapidly getting worse?
I can recall plotting the levels for Muir Parker, Engineering Director, for the subsequent inquest. The levels were getting worse, and of course 'rapidly' is somewhat subjective, but I think it is an accurate statement.