LEGO Technic 9398 Rock Crawler by LEGO Technic : Toys & Games - Amazon.com
REVIEW] 9398 - Rock Crawler - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums
LEGO TECHNIC: 4x4 Crawler (9398) for sale online | eBay
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