⚙️ Drivetrain & Gearing
⚙️ Overdrive (OD/UD)
Gearing one axle to turn faster than the other — normally the front faster than the rear on a crawler or drift car.
Typically 5 to 15%. On a crawler it lets the front pull the truck over obstacles and sharpens steering; too much scrubs the front tires and wastes traction on flat ground.