Tochigi Fuji has introduced the lock-up helical gear LSD, which combines all the operating characteristics of the torque sensing helical gear LSD with an integrated full-locking mechanism to achieve maximum traction output of the vehicle drive axle. The vehicle operator controls the LSD lockup feature by means of a dash-pointed push button. The lock-up helical gear LSD directly replaces the vehicle "open" differential and uses normal gear lube oil, thus axle installation problems are minimized.