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1978 GMC motorhome - $34,795 (Carlsbad)
Gaylord Drive near Conrad Ave
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THE GMC MOTORHOME: THE RV GENERAL MOTORS BUILT WHEN AMERICA STILL DREAMED BIG
Before you look at this 1978 GMC Transmode, you need to understand what you’re actually looking at.
This is not just an old motorhome.
This is one of the boldest, strangest, most beautiful pieces of American automotive engineering ever built.
Back in the 1970s, when most RVs were little more than square wooden boxes bolted onto truck frames, General Motors decided to do something no major American automaker had ever done before.
GM didn’t just build a chassis.
GM built the whole thing.
The frame.
The body.
The drivetrain.
The suspension.
The shape.
The driving experience.
The concept.
The dream.
From 1973 to 1978, General Motors produced the GMC Motorhome — a low, sleek, futuristic, front-wheel-drive land yacht that looked more like something from a sci-fi movie than a campground.
GM was not trying to build just another RV.
They were trying to build the best-driving motorhome ever made.
That’s why the GMC Motorhome was engineered completely differently from ordinary RVs, campers, vans, travel trailers, converted buses, and boxy Class A motorhomes of its day.
Instead of sitting high on a truck frame, the GMC used a front-wheel-drive layout derived from the Oldsmobile Toronado.
That eliminated the rear driveshaft and allowed for one of the GMC’s greatest advantages:
A flat floor from front to back.
That flat floor is not a small detail.
It changes the entire feel of the coach.
You can move through it more easily.
It feels more open.
More livable.
More like a rolling apartment than a cramped camper.
Then GM added rear tandem wheels, independent rear air suspension, a low center of gravity, power steering, power brakes, a wide panoramic windshield, large side windows, and an aircraft-style aluminum and fiberglass body.
The result was a motorhome that didn’t feel like a lumbering box.
It felt planted.
Smooth.
Stable.
Open.
Modern.
Different.
The GMC Motorhome was available in 23-foot and 26-foot versions, with the 26-foot model becoming the most iconic.
Inside, these coaches could be outfitted with kitchens, bathrooms, sleeping areas, lounge seating, heating, air conditioning, plumbing, onboard power, and wild 1970s colors that still make people smile today.
That is why people call these coaches rolling apartments.
That is why owners form clubs around them.
That is why there are still rallies, parts suppliers, specialists, forums, Facebook groups, and restoration communities dedicated to keeping them alive.
Only about 12,921 GMC Motorhomes were ever built.
And the amazing part is this:
Thousands are still on the road today.
That tells you something.
A throwaway RV does not survive 50 years.
A disposable design does not develop a cult following.
A failure does not inspire owners to restore, modernize, upgrade, and protect it for half a century.
The GMC Motorhome was not cancelled because people hated it.
It was cancelled because the world changed.
Oil shocks.
Fuel concerns.
Corporate priorities.
Truck production.
Spreadsheets.
GM pulled the plug after only six years, just as the vehicle was becoming a legend.
And that short production run is part of what makes these coaches so fascinating today.
They are rare.
They are recognizable.
They are collectible.
They are practical.
And they represent a moment in American history when a giant company still had the nerve to ask:
“What if we built something completely different?”
This particular 1978 GMC Transmode carries that legacy forward — but with important upgrades where they matter.
It has the classic GMC design.
The low stance.
The panoramic windows.
The flat floor.
The rear tandem wheels.
The air suspension.
The unmistakable profile.
But it also has a Cadillac 500 V8 upgrade, giving it the strong low-end torque and pulling power you want in a 26-foot coach.
This is the kind of vintage RV, classic motorhome, beach camping rig, weekend getaway vehicle, tailgating RV, surf trip coach, road trip machine, mobile guest room, tiny home on wheels, or camper van alternative that attracts attention everywhere it goes.
It is not a sterile modern box.
It is not a generic Sprinter van.
It is not a mystery project dragged out of a field.
It is a 1978 GMC Transmode.
A rare piece of American road history.
A machine built when GM still dreamed in chrome, fiberglass, V8 torque, and open highways.
And now, the next chapter belongs to whoever is smart enough to recognize what it is.
HERE’S WHAT YOU GET
GMC 1978 Transmode Motorhome
Cadillac 500 V8 • 26 Foot • San Diego, California
VIN: TZE368V100122
Asking Price: $34,795
Serious Buyers Only
This is a fully documented, mechanically sorted, road-ready 1978 GMC Transmode motorhome with a Cadillac 500 V8, major mechanical work already completed, honest disclosures, and over $31,000 invested including original purchase, documented parts, labor, repairs, upgrades, and the Anker power system.
This coach has something most old motorhomes do not have:
A documented history.
A known story.
Real money already spent.
Major mechanical work already completed.
Honest disclosures right up front.
That combination matters.
Because when you buy a 50-year-old motorhome, the question is not just:
“Does it look cool?”
The real question is:
“What has already been done?”
On this coach, a lot has already been done.
The big-ticket, time-consuming, wallet-draining items that scare buyers away from old RVs have already been addressed.
The Engine — Cadillac 500 V8
This coach has been upgraded with a Cadillac 500 cubic inch Eldorado V8.
Big, smooth, low-end torque.
The kind of power you want when climbing grades, pulling through traffic, or heading out of San Diego loaded and ready.
Both cylinder heads have been professionally rebuilt by a veteran machinist.
The Rochester Quadrajet four-barrel carburetor has been rebuilt, set up, and dialed in.
This is not a mystery drivetrain.
It has been opened, serviced, and sorted where it matters.
The Brakes — Done Right
Most buyers overlook brakes until they’re coming down a mountain.
The brake system on this coach was completely rebuilt back to OEM factory configuration by one of the most respected GMC motorhome specialists in Southern California.
Work included:
• New drums
• New rotors
• New pads
• New shoes
• New hoses
• New hardware
• New master cylinder
• New wheel cylinders
• New calipers
• Custom hand-fabricated copper/nickel DOT-spec metal brake lines
• Wheel bearings repacked
• Rebuilt brake booster from Applied GMC
This coach stops the way it was engineered to stop.
Straight.
Controlled.
Predictable.
Major Work Already Done
Cooling, fuel, suspension, steering, brakes, smog, and major reliability items have all been addressed.
Highlights include:
• Complete cooling system overhaul
• New hoses
• New thermostat
• New fan clutch
• New water pump
• New radiator cap
• Fresh coolant
• Complete fuel system overhaul
• New fuel lines
• New vents
• New tank seals
• New fuel filter
• New electric fuel pump
• Generator fuel lines addressed
• Both exhaust manifolds removed, professionally resurfaced, and reinstalled
• New mono airbag suspension kit
• Schrader valves so rear suspension can be filled with any air pump
• New urethane lower control arm bushings
• New steering boot
• Professional window tint
• 90% UV block on windshield and side windows
• Two Dometic Fan-Tastic 12V roof vents installed
• Smogged and passed
• Currently California compliant
Every receipt saved.
Every invoice available for review.
No guessing.
No “trust me.”
No fairy tales.
Mileage
The odometer shows 33,267 miles.
Honest disclosure:
The original Oldsmobile Toronado engine was replaced before my ownership with the Cadillac 500 cubic inch Eldorado V8.
The exact mileage on the Cadillac 500 engine is unknown.
What I can tell you is this:
• Coach shows 33,267 miles
• Cadillac 500 V8 installed before my ownership
• Engine mileage unknown
• Both heads professionally rebuilt
• Major mechanical work documented
• Coach has been driven, tested, smogged, and sorted
Since acquiring the coach, I have only added approximately 750 miles.
The money went into making it right, not wearing it out.
Interior, Comfort & Livability
This is where the GMC separates itself from vans, Sprinters, camper vans, travel trailers, and box RVs.
You can actually stand up.
Move around.
Cook.
Sit.
Relax.
It feels like a real living space, not a cramped metal tube.
Inside you’ll find:
• Flat floor and stand-up room
• Swivel captain’s chairs
• Dinette area
• Dining table that folds down into additional sleeping space
• Full-size mattress included
• Clean interior
• No pets
• No smoking
• Functional bath vanity and shower space
• Classic cabinetry
• Warm wood tones
• Retro 1970s GMC character
• Large windows
• Real room and personality
This coach has soul.
The orange, the brown, the wood, the patterns, the feeling.
You don’t get that from a new plastic-box RV.
Kitchen, Water & Utilities
Included features:
• Refrigerator
• Dual-power refrigerator — electric shore power or propane
• Microwave
• Sink with fresh water system
• Storage cabinets
• Pantry space
• New fresh water tank
• New gray waste holding tank
• New water pump system
• Propane system
• 20-gallon propane capacity
Comfort & Electrical
• Roof-mounted air conditioning
• Dash air conditioning
• Propane furnace / heating system
• 12V electrical system
• 110V electrical system
• Shore power hookup
• 35-foot shore power cord included
Power System
• Onan 4000-watt generator included
• Before purchase, I will have the Onan generator up and operational 100%
• Dual Anker PowerHouse off-grid solar power system included
• Two Anker power stations included
• Brand new unused Anker solar panel included
This gives the next owner multiple power options:
Shore power.
Onboard generator.
Portable solar-backed battery power.
Why I’m Selling
I bought this with my son as a project.
I enjoy projects, and I was excited to bring this one back from the grave.
That’s exactly what I did.
We used it.
My wife, my family, and I took it down to Pacific Beach, over to the bay, parked it, relaxed, and enjoyed it the way it was meant to be used.
The original plan was to turn it into an Airbnb setup.
I even installed a proper 50-amp hookup at the house.
But after setting everything up, I realized I did not want the constant flow of people on the property.
So the plan changed.
What that means for you is simple:
You’re stepping into a coach where the major mechanical work has already been done.
It has been used, tested, driven, smogged, sorted, enjoyed, and documented.
You’re not buying the beginning of the project.
You’re buying the result.
What Makes This One Different
This coach has:
• Clear VIN
• Original service parts identification plate
• Documented history
• Receipts
• Invoices
• Recorded pre-ownership story
• Known mechanical work
• Known upgrades
• Known disclosures
• Known minor punch list
Most vintage GMC motorhomes fall into three categories:
The $10,000 core coach that becomes a full-time job.
The $10,000 to $35,000 survivor coach that runs, drives, and has usable bones, but may still need constant attention.
The $35,000 to $95,000+ restored coach where the major work has already been handled.
This coach sits at the upper end of survivor and lower end of restored.
It is not a $10,000 field project.
It is not a $95,000 museum piece.
It is a documented, mechanically sorted, road-ready GMC Transmode with the big expensive work already done and the minor cosmetic items honestly disclosed.
Everything Included
Included with the motorhome:
• Dual Anker PowerHouse solar power system
• Two Anker power stations
• Brand new unused Anker solar panel
• 35-foot shore power electrical cord
• Trailer hitch
• Hydraulic jack
• Ragusa aluminum entry step
• Ragusa Wind Wings, GMC Motorhome specific
• Custom-fit cockpit sunshade set for windshield and side windows
• Two Dometic Fan-Tastic 12V roof vent fans installed
• All window screens present, not currently installed
• Cheater bar
• Lug wrench
• Spare airbag with piston
• Fresh/gray/black tank systems monitor
• Full-size mattress, clean, no pets, no smoking
• Dining table that folds down into additional sleeping area
• Complete GMC Motorhome owner’s manual
• Archive of technical documents and community resources
Honest Disclosures
The major work has been done.
Here is the minor punch list:
• Paint is cosmetically tired. A repaint would make this coach stunning.
• Onan generator is included and will be up and operational 100% before purchase.
• No currently functioning mechanical parking brake. Use wheel chocks on any grade.
• Roof storage pod was removed to eliminate highway drag. Mounting holes are sealed with epoxy tape.
• Rear left window latch needs attention. Window closes and seals.
• One entry area light is not currently working.
• One roof light needs a bulb.
• Seating is functional, clean, and odor-free, but not showroom quality. Slip covers or reupholstery would transform it.
That is the complete list.
Nothing hidden.
Nothing held back.
That matters.
Pre-Ownership History
This coach has a known and documented story.
The previous owner, Obi, was a hands-on mechanic and GMC enthusiast.
He found the coach advertised online, flew from San Diego to Great Falls, Montana, shipped his toolbox ahead of him, and drove the coach home himself.
The coach had previously made its way from Canada to La Jolla, California, where at some point the original GM Toronado-based engine was replaced with the Cadillac 500 Eldorado V8.
That swap was performed before my ownership.
Obi later took the coach through major repairs and improvements, including brake work, drivetrain work, head rebuild work, propane system work, airbag work, generator work, and other care.
Eventually Obi gifted the coach to his nephew James.
James stored it for a period of time, and I acquired it in October 2019.
Since then, the investment has gone into bringing this coach back to usable, documented, mechanically sorted condition.
Investment Summary
Documented investment includes:
• Original survivor purchase
• Mono airbag kit
• Professional inspection and smog
• Exhaust manifold work
• Carburetor rebuild work
• Fuel pump work
• Cadillac Eldorado air cleaner assembly
• Rebuilt brake booster
• Control arm bushings
• Front rotors
• Complete brake system restoration
• Full fuel system overhaul
• Complete cooling system overhaul
• GMC black tank and plumbing
• Steering boot
• Water pump rebuild
• Ragusa Wind Wings
• Custom cockpit sunshades
• Dash cover
• Professional window tint
• Dometic roof vent fans
• Ragusa aluminum entry step
• Dual Anker PowerHouse system
• New unused Anker solar panel
Total all-in documented investment: over $31,000 including the original purchase, parts, labor, upgrades, and Anker power system.
That does not include 200+ hours of personal time spent researching, sourcing, problem-solving, driving, coordinating repairs, learning the GMC platform, and bringing this coach to where it is today.
The Next Chapter Is Yours
Weekend trips.
Beach days.
Mountain drives.
Coffee by the bay.
Desert camping.
Surf trips.
Tailgating.
Road trips.
A mobile office.
A mobile guest room.
A classic American RV that people actually stop and ask about.
A place to sleep.
A place to sit.
A place to relax.
A conversation piece everywhere you go.
No booking.
No hotel.
No sterile modern box.
Just get in and go.
Asking Price
$34,795
Located in San Diego, California.
Cash or verified funds only.
Serious buyers only.
How to Respond
If you are serious, reply through the Craigslist messaging app, or call or text me directly.
I do not reply by email.
• Cash or verified funds only
• No financing through me
• Located in San Diego, California
• Appointment required
• Test drives available
• Currently insured and smogged
• Valid driver’s license required
• Prior RV driving experience preferred
• Not comfortable driving it yourself? I can drive while you ride.
• If the ad is up, it is available
Disclosure: Photos of the actual GMC motorhome are original. Some exterior backgrounds in select images may be AI-generated for presentation purposes.