When rotating model parts in Shape you can't easily re-align those parts to the X, Y or Z planes. You can get close, but rotation movement doesn't snap to the main planes. But, you can use transparent planes to get a lot closer than just eyeballing it. Here I'm using the transparent planes as an assembly jig for my wheel/tire assemblies. As I move the wheel/tire towards and then through the plane, I can see the edges of the circle pierce the plane and see what needs to be adjusted. You can see that I can't get it perfect, but it's a lot closer than it was. Download the transparent blue texture from the model to your textures folder or make your own. - LATER - I found that the transparent blue made it hard to see the blue center points when making circles, so I switched it to a transparent yellow instead. Just a suggestion based on a lot of frustration on my part from trying to build trucks in Shape. Have fun!