Module 2 – Traction Management Systems & Differentials
In extreme terrain, traction management is as much about physics as it is about equipment.
Open differentials allow wheels to spin at different speeds but will send torque to the wheel with least resistance — a problem in diagonal wheel lifts. Limited-slip differentials (LSDs) mitigate this by applying some torque to both wheels but can still struggle in very low-traction environments.
Locking differentials are the gold standard for technical crawling. Mechanical lockers (e.g., Detroit Locker) provide constant lock engagement, while selectable lockers (e.g., ARB Air Locker, Eaton E-Locker) allow on-demand control. Knowing when to lock is crucial — locking too early in a turn can cause understeer, while locking too late may leave you stuck.
Electronic traction control uses the braking system to limit wheel spin, simulating a locked diff. While helpful, it generates heat and can fade on long climbs. Experienced drivers know to blend mechanical and electronic systems strategically.
A torque bias ratio (TBR) chart from your differential manufacturer can guide you on exactly how much power can be sent to the high-traction wheel — a critical figure in rock crawling.
