[cnavarro]

I will say that the single row bearings are not tolerant of debris at all where we know the dual row bearing will take much more abuse and just keep chugging along even laden with FOD (but not indefinitely). It's quite possible a PO had the IMS Retrofit procedure carried out as a reactionary repair because the original bearing had failed.

I would be curious to see what's in the sump.

There usually isn't tell-tale signs of damage to the intermediate shaft like there is with a single row bearing so it's hard to get a complete picture. As part of our qualification procedure when rebuilding an IMS, we spin test the shaft and check for runout in the gear and housing bore to detect damage to the intermediate shaft because often shops send us IMSs with the original bearing already removed so we don't know what condition the original bearing was in.