In the 1970’s, General Motors entered the RV market. Drawing on the exuberance of the times, the company set out to create the ultimate American Motor home. Their aim was to produce a top-of the-line vehicle with cutting-edge design and construction, not just another competitor in the already crowded vacation vehicle market. The common design in this era was a boxy, ungainly and top-heavy unit on a truck chassis. The GMC vehicle was intended to be a completely new design in every way. Design work began in 1970, with the market introduction planned for 1973. “Doesn’t look like a box or ride like a truck” was the GMC ad slogan. foodeenation.com
The new vehicle would be unusual for this era in several ways. First of all, it was to have a front wheel drive, a rare concept in cars of that day and unheard-of in mobile homes. The drive train and suspension were taken from the design of the Oldsmobile Toronado. The 265 horsepower 455 cubic inch Oldsmobile engine was attached to a Turbohydramatic 425 transmission with torsion bar suspension. The rear suspension was a product of GM’s bus design, using dual swing arms, one leading and one trailing, with a single air spring on each side. Instead of a auto body steel, the body was to be made of lightweight aluminum and molded fiberglass-reinforced plastic such as was used in the Chevrolet Corvette.
The front wheel drive and independent swing arm rear suspension brought great improvement to the standard motor home design. The lack of drive shafts and axles underneath the coach allowed a very low floor height, leading in turn to a low overall vehicle height and lower center of gravity. Aside from easier entry and exit, this reduced rollover risk and wind resistance and made the vehicle much safer and easier to operate for buyers accustomed only to car driving. A six-wheel braking system, with disc brakes on the front and drum brakes on all four rear wheels, further enhanced drivability.
Previous motor home design focused mainly on the use of the vehicle as a temporary home once it had reached its destination, an extended stay in a mobile home park or a camping spot. Ease of getting to the destination was of secondary concern, and cumbersome handling on the road was taken for granted. GMC made a special point of targeting this feature for improvement by adding visibility from the driver’s seat with a panoramic expanse of glass. firmnews360.com
The motor home was featured in 23 foot and 26 foot lengths, fairly small even for this era. Nowadays, much larger models are common. The motor home’s interior design was compact, with no permanent sleeping areas in the original design. All beds were converted from seating areas when required.
Hot water was provided by water heaters using engine coolant loops, which produced water so hot it could actually present a scalding hazard since coolant temperatures usually exceed 200 degrees Fahrenheit. The refrigerator was powered by a standard automotive battery, adequate only for overnight use before recharging. sanforex24h.com
The prototype was first displayed in May 1972 at the Transpro ’72 trade show in Washington, D.C. Production started in 1973 with two models, Model 230 and Model 260, 23 and 26 feet long respectively. They were sold with a finished interior for the public as well as unfinished to other RV manufacturers such as Avion and Coachman, who then provided their own interiors before reselling to consumers. 30 different floor plans were available, and models were priced from $35,000 to $40,000.
The GMC vehicle changed slightly over time, the most notable alteration coming in 1977 when the 455 cubic inch engine was replaced by a 403 cubic inch model in response to the energy crisis. This decade caused hardship for all RV manufacturers as the increased price of fuel pushed large gas guzzling vehicles out of the market. The GMC motor home had never sold at high volumes, and the company decided that the RV production facilities could be more profitably used to make light trucks. After the manufacture of 12,921 vehicles, production of motor homes was discontinued after the 1978 model year.
Almost immediately after production ceased, GMC motor homes became collectors’ items, with owners’ associations being established to provide parts and service for these vehicles. Small manufacturers and garages developed a cottage industry servicing them. In 1992, as General Motors prepared to scrap all remaining tools and parts, Cinnabar Engineering purchased all the motor home manufacturing supplies and negotiated a deal to continue to provide parts for the discontinued vehicles. In 1992, a monthly magazine called GMC Motor home Marketplace was introduced, and in 1994 Cinnabar started publishing a quarterly newsletter called GMC Motor home News.