zak99b5
Well-Known Member
If it's like my 2010 Suburban system, 4WH locks the transfer case. Need to be on slippery surfaces, or the drivetrain will jerk and bind. On 4WAuto, a clutch in the transfer case allows the fronts to engage/disengage as needed, so there's no binding. So it's fine to use in all road conditions. But I use 2WH to use the clutch in the transfer case as little as possible and save a little gas.