PACCAR Incorporated (Paccar) is recalling certain model year 2014 Kenworth T170, T270, T370, T440, T470, T660, T680, T700, T800, T880, C500 and W900 trucks manufactured July 1, 2013 through September 17, 2013. In the affected vehicles, the plastic housing of the Stop/Tail/Turn (STT) lamp can shrink and allow the light bulb to fall out of the mounted retention ring. As such, the Stop/Tail/Turn light would not be illuminated, and the vehicles do not conform to Federal Motor Vehicle Safety Standard (FMVSS) No. 108 “Lamps, Reflective Devices, and Associated Equipment.”