You could try a different PDF preset, but otherwise I think those are simply limitations in the Apple Preview you have to live with unless you really flatten everything.
I am working on a logo for a client and I have made it from 3D Classic in Ilustrator. The logo exports fine as a PNG, JPEG etc but when I try to export as PDF, SVG or EPS it looks fractured and distorted, but only while being viewed in previews etc and looks normal on Adobe Acrobat.
How can I get it to look normal as one of these file types as I don't want my client to think that it is broken.
Hard to say what you did there without any info about the layer structure and settings for the appearance as well as other possibly relevant details. have you actually tried manually rasterizing/ expanding the artwork before saving?