I picked up an R180 differential out of a 1972 240; hopefully less noisy than the one in my 1973. These are the exact same part.

The replacement differential is missing the side flanges and stub axles and I need to get them out of my other rear-end. I know these stub-axles are known as "bolt on," and there's a bolt that apparently attaches the flange to the (splined) stub axle. But what is holding the stub axle itself into the differential? A clip? Where? Or do I just force out the stub axle, using the attached flange itself. I don't find a clip shown in the parts breakout; attached. Thanks.

The flange and shaft are one piece. It is held in by the long bolt that threads into the center of the flnage/shaft. The bolt threads into a nut at the center of the differential. I think it is item 7 in the diagram you posted. You should be able to remove the bolt and withdraw the shaft. Some force may be required since the fit with the bearing is close.

Aha, great. Thanks for answering. Is there anything that holds that nut in place, so that I'll be able to get the bolt into it when I re-attach; without taking the diff. further apart? (Yes, it's item 7; "Nut - lock, side flange.")

No need to answer. Found threads in the diff. lacking the stub axles. Removed bolts and stub axles from the donor.