OTC 1916 Truck Wheel Bearing Locknut Socket, 4-3/8", 6-PointOTC Tools OTC 1916 Truck Wheel Bearing Locknut Socket, 4 3 8", 6 Point. These sockets have a 3 4" square drive opening, permitting the use of an extension and torque wrench to tighten the locknut as required. Locknut removal and installation is simple, even when wide rim wheels are involved, since a long extension may be attached to the socket to provide the necessary clearance. Sockets are made of high strength steel; openings resist "rounding out."