The 26 foot, 12,000 pound Antique Hot Rod with Plumbing -- GMC Motorhome

The motorhome, with production running from 1973-1978, had a front-wheel-drive transaxle used in the Oldsmobile Toronado and Cadillac Eldorado with an Oldsmobile 455 cu in (7.5 l) V8 from the Toronado, but the later models made use of the 403 cu in (6.6 l) V8. Both used the GM-designated Turbohydramatic 425 automatic transmission, with a wide chain drive to connect the output of the longitudinally oriented engine to the transmission. The final drive was connected directly to the transmission, and power was fed to the front wheels using half-shafts that ran under the front portion of the engine. The engine was fueled with regular gasoline stored in two 25-US-gallon (95 l) tanks.

The GMC was equipped with front disc brakes and drums on all four rear wheels. A popular owner modification puts disc brakes on a pair, or sometimes all four rear wheels as well. The front-drive configuration eliminated the driveshaft and rear differential and solid axle found on most front-engined motorhomes. As a result, the floor could be designed only about 14 inches (36 cm) above the roadway. The low floor was too low for a rear cross axle, and GM designed the rear suspension as a tandem pair of wheels, mounted on bogies which rode on pins attached to the sides of the low-profile frame. With the exception of the wheel wells, the rear suspension does not intrude into the living space. The rear bogies are suspended using a double-ended convoluted air bag that is pressurized by an automatic leveling system to maintain the designed ride height. The leveling system can also be manually controlled to level the coach at a campsite.

Nearly four decades later, the GMC Motorcoach is still ahead of its time in terms of design and engineering. Reliable big block power and torque, low step in height, front wheel drive technology, light weight and a fanatical following have made these units live on and on well beyond their production run. The air ride suspension combined with its own aluminum frame (rather than being truck based like that is still being used today!) give it the ride and handling that a soccer mom would normally experience in her minivan!

Our 1974 coach has a freshened drive train with its big block having been gone through and a new torque converter and gear set (for better mileage!!) installed by the last owner. The 6kw Onan Genset has a fresh tune up and is ready to go. The roof top A/c blows cold and the Propane Furnace will keep you toasty on fall trips. This unit is pretty close to original, all the way down to the central vac system and yellow Formica counter tops. All and all a very nice coach that is ready to cruise RT 66 this summer.

Go through the pictures and if you have any questions at all give us a call. Also be sure to check out May 2011 Hemmings Classic Car for a review of the coach and its collectability. Also Included in the sale is a copy of “Stripes” with Bill Murray, a timeless classic show casing the GMC motorhome “and that’s a fact Jack!” www.fatmansgarage.com

1974 GMC Motorhome