OK, lets' try to clarify this alittle bit, shall we. More to the point, the actual "C" clip itself will not break, but the area where the clip goes is machined into the end of the axle and is a fairly deep cut. Now, if you manage to "shock" load this axle shaft hard enough, and the axle goes to twist, this is the weakest point in the shaft, so, tends to be the point that breaks. Now you are back to the problem of keeping the wheel attached. And yes, regardless of "C" clip or bearing retainer design, the axle shaft does need to changed. I have had the "mighty" D-44 rear axle decide to crap the wheel bearings and then the axleshaft would leave, so it does happen. It is one of the downfalls of the light duty, or semi-floating, axle design. I have even had the Chrysler 8 1/4 do the same thing.