CMW 1:87 GMC PD-4103 Union Pacific Interstate Bus: Destination, E Los Angeles

The GM PD-4103 was a single-decker coach built by GMC, in the United States, in 1951 and 1952. It was a 37- or 41-passenger Parlor-series highway coach and was an improved version of the earlier PD-4102 "transition" model. A total of 1501 were built, 900 in 1951 and 600 in 1952, plus one that was converted by GMC from a PD-4102. In early 1953, this model was replaced by the groundbreaking PD-4104 "Highway Traveler". The PD-4103 competed directly with, and surpassed in sales, a competing model from ACF-Brill Corporation, the IC41.

The GM Truck and Coach PD-4103 was the last in a series of low-budget "conversion" parlor coach models which were, in actuality, based upon the basic Yellow Coach/GM Truck and Coach transit bus models which first appeared in 1940. Favored GM customer Greyhound Lines had already been given a near monopoly on the PDA-3701/PD-3751 "Old Silversides" models, which were in part designed by Greyhound themselves. In order to answer complaints from arch competitor Trailways and other independent operators about being locked out from purchasing the PD-3751 model, GM simply took their existing 96" wide, 35' long suburban transit model, added more luggage bay space underneath, added sliding highway-style side windows, added reclining seating, and shortened the overhung portion of the front end by moving the front axle forward using a new front end from the wartime Yellow Coach "Victory Cruiser" model. This was the PD-4101, which appeared shortly after the end of World War II. GM created the model PD-4102 by restyling its PD-4101 in 1950 using a distinctive new front end with the destination sign below the windshield and a new, restyled rear end which used a full-width engine access door, an aluminum alloy bumper to match that on the front and a "post-less" picture window in the rear which used biradial curved glass (a new development by GM supplier, Libbey-Owens-Ford), replacing the divided flat transit bus-type rear windows found on the PD-4101. The front end styling job on the PD-4102 was reactionary, as it closely mimicked the striking styling of the IC41 intercity bus built by ACF-Brill Corporation in 1947-1954, a model bought in large quantities by Trailways to compete with Greyhound Lines' successful and much more efficient PD-3701/PD-3751 "Silversides" models. Mechanically and electrically, however, the PD-4102 was mostly a carry-over model from the PD-4101, including the optional refrigeration unit for air conditioning which used a four cylinder Continental "pony motor" driving an Ingersoll-Rand "oil-less" rotary vane compressor rated at five tons, a unit identical to that used by the PDA-3501/PD-3751 for Greyhound Lines. Only 116 were built.