I found some interesting pictures of CFM56-3 and CFM56-7B engines on the database. What I found most interesting was the differing generator setups, and the changes this makes to the fan cowlings. It appears the -3 has a separate CSD / generator set-up, whilst the -7B has an IDG. Was it possible to get an IDG fitted to the -3?
Photo © Martin Hodgson
Photo © Irfan Caliskan - AirTeamImages
Photo © A J Best
Photo © Carlos F
The fan cowlings of the -3 seem to be much longer to allow for access to the generator. Is the remaining part of the inlet cowl readily separated from the rest of the engine? The -7B has an inlet cowling of the type that is more familiar to me.
The side mounted gearbox is an interesting set-up. From the looks of it, there appears to be what I assume is a shrouded shaft at the top rear of the gearbox, which itself ends up at another box like structure. Does this box contain a set of bevel gears? Does the driveshaft from the engine core come out "sideways" through one of the fan case struts?