Slides through two holes in the steering block and helps the vehicle wheels turn. Report this Word Added by: snakebiteoffroad

The main fastening member between a fifth-wheel hitch and trailer.

the number 5 pin

The 5 pin in some localities, the head pin in others.

The trailer's part of the articulation of an articulated vehicle

The coupling pin welded or bolted in the centre of the front underside of a semi-trailer chassis, which couples to the fifth wheel of the towing tractor or dolly convertor.

Front pin - also known as the "Grumble and Grunt" - geddit?. To help you, (and by God our lot need all the help they can get), it's usually marked by a stripe or two around it's neck

A coupling pin centered on the front underside of a chassis; couples to the tractor.

The pivot on which the fifth wheel (q.v.) turns