Ultimate upgrade for the 9398 4x4 crawler with pendulum steering (no servo needed). I also made a pendulum steering file in the rebrickable link you can download and have a closer look
9398 - Lego Technic 4x4 Crawler - Page 40 - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums
Amazon.com: LEGO Technic 9398 Rock Crawler by LEGO Technic : Toys & Games
4 x 4 Crawler : Set 9398-1 | BrickLink
LEGO Technic 9398 4x4 Crawler MOD | Nikolay Gamurar | Flickr
LEGO Technic 9398 Rock Crawler by LEGO Technic : Amazon.co.uk: Outlet
Lego Technic 9398 Rock Crawler Preview | The Lego Car Blog