I don't have your answer. (So you can stop reading my post now if you want.)
I have had several rear ends sitting on the floor with the axles attached not wanting to take the axles off due to the grease mess they would likely create, and the fact that I obtain little benefit by removing the axles. However, I believe that there's just a clip that holes them in. This isn't what holds the axle on the car when in use though.
BTW: I have found that the w114/115 rear subframe is the same as the c107 SLC and at least some w123 cars. The differentials on SL r107 and SLC c107 are the same. Therefore I assume that any 107 differential should be able to bolt into a w114/115, probably even w123 differentials too. Unrelated, the R/c107 front subframes are identical to the w114/115. So it seems the SLC is basically a w114 coupe that might be equipped with a common m110, or maybe a v8. I just find it interesting.
this is true, regarding the rearend,
i have a w115 with a 2.69 diff from a w116 450SE 6.9
a w115 with a 3.07 from a s123
a w115 with a 2.88 from a s123
a w123 with a 2.47 from a w126
the driveshafts/axleshafts from a w116/r107/w126 wont fit the w115/w123,
the diff will.
so a w126 differential will fit a w115 with the stock w115 driveshafts, (or w123 driveshafts)
al differentials from the w115/w123 up to any benz r107/w126/w116 up to 1985, (not 1986 since they are of a new design) will swap flawlessly.
althou, the cardanshaft/driveshaft from the transmission has a larger flange/yoke on the v8 equipped cars. and thus needs to be swapped (on the differential, or swap the driveshaft/cardanshaft)
for differentials, their ratios aswell as fitment, and swap guide for w115/w123
yes, as soon as you remove the back cover, what holds the driveshafts/axleshafts is a tiny metal clip, with a bent slim metal-rod they are somewhat easy to pull out.
with a new diff or new shafts, you need to swap or adjust the shims/washers for the correct spacing of the driveshafts, suchs that they dont have any large play in or out, or sits to tight and destroys the thrustring in the differential