Q: cannot tranfser audiobooks to new ipod (lost old one)

Recover your iTunes library from your iPod or iOS device

For non-iTunes purchases you need a third-party computer app like one of those discussed in the above. I use iFunBox

Since your audiobooks are in your iTunes library, you may just need to set up syncing for audiobooks in iTunes (to your new iPod).  The screenshot below shows upper left corner of my iTunes window, showing the iPod's device button (circled in red)

Click that device button, to show iPod's Summary settings screen.  Along left side of window, in the sidebar, under Settings, click Audiobooks.  To the right, the iPod's Audiobooks settings screen appears, where you tell iTunes how to sync audiobooks to iPod.

Checkmark box for Sync Audiobooks.  This turn ON syncing for audiobooks.  Below that, set it up as desired, to sync all audiobooks or a selected portion.  Then click Apply.  Going forward, iTunes keeps iPod in sync with your iTunes audiobooks library, based on how you set up that screen.

If that's not your problem, please post back with more details.