How do you download an audio book without losing music when you sync it?

Greetings Wildcat66,

After reviewing your post, it sounds like you want to add audio books to the iPod shuffle. I would recommend that you read this article, it may be able to help the issue.

iPod shuffle: Playing audiobooks and podcasts - Apple Support

Adding audiobooks and podcasts to iPod shuffle

The Autofill feature of iTunes will not add audiobooks and podcasts to any iPod model. They can be manually added by dragging them to the iPod shuffle in iTunes.

Thanks for using Apple Support Communities.

Take care,

Mario