Out of The Box: 1978 GMC Palm Beach Motorhome – NOW $31,500

by | Sep 2021 | Classifinds, Truckin Tuesday

September 26, 2021 Update – After a two-month pause following the expiration of their last listing, the seller of this GMC motorhome just posted a fresh listing for it.  This time they increased the price back up from their last listing of $29,500 to the revised $31,500.

August 2, 2021 Update – We just confirmed the listing for this GMC Motorhome “Classifind” expired, so with no replacement found we’re assuming this ride “Sold?” until we come across a new listing for it.

June 25, 2021 Update – One month after we first featured this vintage GMC motorhome, we came across a fresh listing indicating the seller decided to lower their asking price from $32,000 to $29,500. Time will tell whether moving the asking price below thirty large will be enough for the next caretaker to make the jump into this unique motorhome.

Through the mid-seventies, despite its complex organization and bean-counter-driven culture, General Motors still had pockets of innovation afforded by their world-leading market share up until that point.  From this Engineer’s perspective, the brightest idea to come out of GM in the 1970s was the 1973 to 1978 front-wheel-drive Motorhome.  These innovative motorhomes remain highly sought after to this day, and this 1978 Palm Beach Edition in all of its Avacado Green Plaid glory was originally listed in June 2021 and currently relisted here on Craigslist in Bethlehem, Pennsylvania appears to be a mildly updated driver-quality example offered at $32,500 currently. Our normal pricing sources do not apply in this case, but finding a similar 1977 GMC Motorhome on Bring a Trailer that sold in March for $32,500 at No Reserve is likely not a coincidence.

GM’s GMC Truck & Coach Division designed and manufactured their innovative motorhome from 1973 through 1978 in Pontiac, Michigan. It was and remains the only complete motorhome built by a major automobile or truck manufacturer. Unlike conventional box-on-frame RV design that largely remains in place today, GMC’s design used a front-wheel-drive design to provide a much lower drive height.

Specifically, GMC engineers used a version of GM’s front-wheel-drive Unified Powerplant Package (“UPP”) then being used to power Oldsmobile Toronados and Cadillac Eldorados. In motorhome form, GMC first elected to use Oldsmobile’s 455 cubic inch big block (7.5 l) V8. however, but the later models such as the example featured here made use of the Oldsmobile 403 cubic inch mill once the former was phased out. V8. Transmitting power to the front wheels was the roller-chain-driven Turbo-Hydramatic 425 automatic 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. twin-fifty gallon tanks mounted safely within the frame rails, fed the massive V8.

GMC Motorhome Chassis – Courtesy Wikipedia

GMC Motorhome came equipped with front disc brakes and drums on all four rear wheels. The front-drive configuration eliminated the driveshaft and rear differential and solid axle found on most front-engined motorhomes. Consequently, the floor could be built with about 14 inches of clearance above the roadway. The floor was too low for a rear cross axle, and GM designed the rear suspension as a tandem pair of wheels, mounted on bogies that 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 reversible sleeve airbag 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.

GMC built motorhomes in either 23-foot or 26-foot length, with about 90% of the total production being the latter. All GMC Motorhomes are 96 inches wide and about 9 feet tall including the usually-installed roof air conditioner. Interior headroom is six feet, four inches.  The gross vehicle weight rating for the 23-foot coach was 10,500 pounds and 12,500 pounds for the 26-foot coach. Most units came equipped with thirty-gallon freshwater and matching holding tanks

Body construction consisted of a rigid frame made of welded aluminum extrusions. The body frame was mounted on the chassis steel ladder frame using body isolators. The floor was marine plywood, except where it sloped up at the extremities, where they were plate aluminum. The body panels for the most part were made of fiberglass below the waistline frame extrusion and at the ends while the upper side body and roof panels between the ends are sheet aluminum. GMCs are notable for their large expanse of windows, which redefined the RV industry at the time. They often had luxury features common on upper models of GM brands, such as cruise control, air conditioning, AM/FM/8-track sound systems, an aluminum/fiberglass body, as well as air suspension.

If you can get past the narrator’s monotone voice, the content presented about the GMC Motorhome on the OldCarMemories.com YouTube Channel is a must-see:

 

Here’s the seller’s detailed description:

“This listing will change as I update it, there is a lot to go over as far as upgrades that were done.

1978 Palm Beach Motorhome
Inside revamped resto-mod style. Retaining original aesthetics, but more functional.

The Good!

Runs Great!
403 Engine, purrs like a kitten
Inspected to 7/21
Brand new windshields installed last year! Crystal Clear
Front Wheel Drive
35,000 Miles (Not 100% on the exact number, this is close, I will update)
6x Alcoa Wheels with semi new tires, almost no wear on the tires (Can include original wheel/tires as well if you want them for emergencies, also spare is original wheel)
2 Awnings, one large “front” awning and smaller half width awning on the driver side
Loud Electric “air” horns
Hard to find period correct lawn chairs with fabric that is an exact match for the original awnings.
New Touch Screen Navigation/Stereo with back-up camera and “always on” mode for rear-view use
Driver / Passenger Seats re-upholstered
Original Bunk Beds removed and replaced with period correct barrel chairs from another Palm Beach (Original Bunk included with sale if for some reason you wanted to change it back)
Small dining table between the barrel chairs, stained and installed
Original Dinette removed and replaced with an amazing piece of motorhome furniture, a couch that folds out into a bed in addition to securing a hide away 43″ TV that runs on a motorized lift.
All Outlets replaced, Outlets at the front of the coach include USB Charging Ports
New Countertop
New Faucet
New Water Filter
New Stovetop
New Microwave
New recessed lighting throughout entire motorhome
Working Furnace
Working On Board Vacuum system (will need bags)
Refrigerator replaced with a 2-way Electric/Propane model
New Toilet
Entertainment System Area for running the Main TV and a Rear Bed TV(read bed tv not installed, but cabling is ready to go) This will include a stereo receiver to switch between various inputs, Small PC, XBox 360 (Included) or Playstation (Not Included), and TV Reciever for use with the on board antennae. Both TV runs are HDMI.
New Water Heater / Tank
New Headliner
Both Rooftop Air Conditioners blow cold
Rear Dining Area that folds into a bed (Table is included, just forgot a picture, it mounts between the rear seats)
Blanket box and wood shelf on opposite side rebuilt by same carpenter that created the Couch/TV/Bed Hide Away piece, Real wood stained!
New hide-away brass outlet on the blanket box
All new window treatments with new pull down privacy shades.
All new carpet (automotive in the front and SHAG in the rear) and water proof vinyl/wood flooring in the center/living/kitchen area with sound deadening underlayment
Brake system completely redone last year, brakes are working excellent
Entire electrical system gone through and wiring replaced
Working 6k Onan Generator reconditioned last year
Gas Tanks replaced last year
Carburetor replaced with a specially tuned one specifically tuned for the GMC Motorhome by Ken Frey (Local GMC Motorhome expert/mechanic, no longer in business)
All fuel lines and filters replaced
New Belts
Oil cooler lines just replaced with new stainless steel high pressure lines https://www.gmcrvparts.com/product-p/(8-2056).htm
Exterior paint should shine up fine with some effort
New Through the Bumper Hitch $500 installed https://www.gmcrvparts.com/product-p/ap32.htm
New “Alex” Airbags 2 on the coach, 1 backup in storage. $750 each! https://www.gmcrvparts.com/product-p/g00001.htm
New Power Steering Hose recently installed

The “Bad”
This list is mostly external
Could use new pin stripes and side body molding to really make it sharp
Door got banged a little bit when previous owner was backing out of some mud and it was left open (this was before the entire revamp of the coach, but you may want to do a little body work on the door to get it 100%)
The rear bumpers need to be re-chromed
The fresh water tank will need to be replaced before you can boon dock (camp without a camp ground hookup), normal camp ground water hookup works fine.

I will update this listing if I think of anything else.

Show or go: what would you do with this restored Triumph?  Comment below and let us know!

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