OTC Tools OTC 1975 Truck Pinion Sockets. OTC has designed and built these sockets to have the proper clearance for yoke and locknut assemblies on a variety of truck transmissions and differentials. Sockets have 3" of useable depth, 4" overall length. Eliminates modifying standard socket to provide necessary clearance. All of the following are 3/4" drive, 6pt. sockets.