So the axle is flush, and doesn't stick out? And the accompaning nut is internal so you just see the last thread or two? My 175 is totally different with an honest-to-god axle with two external nuts. I looked at the 550 and it seemed like the rusty end of a sheared off something or another was visible about 1/2 way into the wheel shaft, thought it broke and was 1/2 gone, with the other 1/2 in the process of working it's way through the shaft after having lost it's nut.
