I see in the Form 30523 D4400 engine service manual for the D4 it recommends drilling the main bearings on the pony engine with a 15/64” drill and then finish reaming to 0.249-0.250” for the pin. I see on my NOS bearing there’s already a hole for the pin, haven’t unwrapped it from the cosmoline paper yet as I’m a long way from installation, but is that process still required for the replacement bearings? My NOS from Florin is dated 1946 so I’m assuming it is. But before I source a reamer I thought I’d check it’s a required step.

Tony

Thanks very much for the info.