Ok so I'm too broke to buy an xo-1 right now so I've been purchasing parts to build one as I can afford it. While doing this I have my 4x4 slash torn apart for some new bearinngs a few upgrades and maint. I have noticed that the differential housings for the slash and the xo-1 are identical, so are the internal geers and bearings. The turnbuckles are the same as well. These parts are a lot cheaper for the slash so if you find yourself needing some of those parts for repairs look at getting the slash ones they are a lot cheaper.