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1 Of 36: 1975 GMC Transmode

General Motors got into the motorhome business for a short time in the 1970s. It was a front-wheel drive touring machine that was built in 23 and 26-foot configurations on a modified Olds Toronado/Cadillac El Dorado chassis with a 455 V-8 engine. For moving people, they called it the GMC Motorhome, but they also built a version for moving cargo, dubbed the Transmode. The latter was just 25 percent of production and is represented by this 1975 edition that appears to be in good condition. It’s located in Millburn, New Jersey and available here on Hemmings Classifieds for $6,900. Our appreciation to Mitchell G for finding this one for us!

The Motorhome/Transmode was made by the GMC Truck & Coach Division for 1973–1978 and was the only complete motorhome built by a major domestic auto/truck manufacturer. Besides using FWD, it was noted for having a fully integrated body and – unlike most motorhome manufacturing – GMC designed, engineered, and built the entire vehicle (including interiors) in house. Empty shells were also supplied to other RV manufacturers for interior outfitting and to specialty manufacturers for custom outfitting, ranging from mail delivery and mobile training facilities to people movers and ambulances. Source: Wikipedia

No doubt as a way to reduce expenses, the transaxle was sourced from the E-body Olds/Caddy with an Oldsmobile V-8 and GM’s 425 Turbo-Hydramatic transmission. They used a wide roller chain drive to connect the output of the longitudinally installed engine to the tranny. 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.

Across six model years, the Motorhome/Transmode saw production of just under 13,000 units. Of that, 3,200 were the stark Transmode versions which saw just 461 copies in 1975. Drilling down further, only 36 23-foot Transmodes were built in 1975, the lowest production for any year and that length in Transmode trim. So, the seller’s version of the Transmode is a rare beast.

The Transmode lacked all the creature comforts that the Motorhome offered. It was basically a large box for which most of the interior compartment was comprised of air. Besides a bucket seat for the driver, it also had a small bench seat that could seat maybe two other people. We don’t know if the seller’s Transmode was purchased originally for commercial use or just something to haul around a lot of stuff for the owner. This one has 106,000 miles, which is not a lot for a carrier of this nature. We’re told its in good condition, which we assume also reflects its running order. The white over grey paint is a bit faded across the combination aluminum and fiberglass body. There is no evidence of rust on any parts that could be subject to that bi-product of Mother Nature. The photos provided are low resolution and taken in portrait style; sellers should always be encouraged to take high-resolution, landscape photos to support their wares.

Condition of these kinds of vehicles dictates price. I found two online, one for $10,000 and one for $50,000, and both were Motorhomes and not the more pedestrian Transmode. If this thing needs no major work, perhaps it could be an inexpensive way to have something along the lines of a Dodge/Mercedes Sprinter van. A friend of mine has one of those to pull a pop-up camper and haul motorcycles, something that this rolling storage container could easily do. However, most of the bounty will have to be loaded from the rear and shoved forward as mid-section side doors are not part of the equation.


  1. Connecticut Mark

    Cool but sprinter diesel get much better mikes per gallon than this monster motor.

    Like 3
    • Chris

      But It won’t be as fast!

      Like 6
      • Richardd Adams

        Actually, I spent 5 years and 50k miles in a Sprinter Van. It was comfortable with air con fitted standard.
        The 2,8 turbo diesel was governed to 85 mph – uphill and downhill – it would carry 2500kg and tow 2500kg, without the empty performance being affected.
        It delivered a constant 24 mpg empty or loaded.
        That large 50 m3 vehicle was more economical than my VW Westfalia, a quarter of its size and was sold, running perfectly at 250k miles. Never brokedown, ever.

        Like 2
  2. ACZ

    How can you attempt to compare underpowered rigs like Sprinters and Transits to this beauty? When people can’t find anything else to complain about, they bellyache about fuel economy. A whiney way out.

    Like 29
    • wjtinfwb

      Perhaps you’ve never driven an EcoBoost Transit, underpowered it is not and it would leave the GMC in the dust. Everyone wants to wax eloquent about old cars and huge torquey engines, the reality is, they weren’t that fast and as emissions equipment took hold drivability was compromised. A V6 Camry or Accord would leave 90% of muscle cars in its wake then deliver 30 mpg on the way home.

      Like 6
      • ACZ

        I have and want no part of it.

        Like 6
      • R.Lee

        Trasit? WAT!

        squirrel cars acord camree wut?

        Like 1
      • xrotaryguy

        We’re completely missing the point though. This thing is COOL! A Transit can’t compete in that department!

        Like 1
    • Big Al

      WTF, comparing camry,accord to old muscle, just plain millignorant!

      Like 2
  3. PaulR

    The low deck height is a huge plus. Not sure it would be suitable for door to door running that a sprinter does, but for hauling loads over the road, you couldn’t beat the ride.

    Like 11
    • Matthew Terry

      You could also probably modify it to dump the rear air bags and lower it even more, with that overhang, probably all the way to the ground.

      Like 2
    • Terry Melvin

      But no mid door access limits it’s usefulness. This rig would make a good DIY motorhome conversion.

      Like 6
  4. Arby


    Like 12
  5. Jakespeed

    Modify it to make the best car hauler ever. A GA Tech grad and car
    enthusiast did this and sold it in B.A.T. ‘bout a year ago.

    Not to put down a Sprinter’s fuel economy, but the ability to get service, parts (and filters) for the inline 5 or V-6 Turbo diesels isn’t that good, so I’ll lean toward older technology and lousy fuel economy over the Sprinter’s frugality with fuel.

    Like 14

    THIS is the cargo / RV vehicle you wanna make happen. Most RV manufacturers get way too cluttered with their interior designs.You want to add just what you need…and the cargo version allows that.I bought my RAM Promaster for that reason. I’d snap this up if I was in the market just now.

    Like 7
  7. Martin

    Most of the Transmodes were built into motorhomes. GMC supplied the shell and drivetrain for others to finish, and most but not all became motorhomes. And most of the 23 footers that left the factory were unfinished Transmodes as opposed to the 26 footers which were mostly sold as finished motorhomes. .

    Like 4
  8. Matt c

    I would love to turn this into a micro car hauler, MG midgets are 4’ wide and lots of little stuff could fit in a 5’ wide door. Dont need a trailer unless you buy 3 … lol

    Like 5
    • Little_Cars

      I’ve been known to do that, Matt! Bought three Midgets, put the two shells without drivetrains, bumpers and wheels sideways on a flatbed trailer. Still had to drive back to collect Midget #3. You’d want to make sure that diamond plate rear step/bumper could be reconfigured with a fabricated ramp before putting any Spridgets inside this Transmode. Unless, of course, you lift the cars up inside like we used to do in college.

      Like 3
      • Matt c

        I have a midget and a sprite and a Renault Dauphine and a Triumph Herald .. under 14’ long and 5 wide … looking at another herald and a Hillman Husky … wife will kill me but a car hauler would make things much easier than a car dolly or tow bar…

        Like 3
      • Little_Cars

        Matt C I feel your pain. There are lots of beat up 25-30 year old rollbacks and tow trucks on my local classified that lure me into calling but I never do. I’d love a vintage ride to snatch up the occasional impulse purchase but the wife barely allows me to neatly store what I have on concrete in an area of our big barn.

        Like 3
  9. Ike Onick

    NASA Astronaut hauler.

    Like 2
    • Dave

      They don’t do that nowadays. Tesla provides the transportation for astronauts for SpaceX.

      Like 4
    • xrotaryguy

      I thought NASA only used Airstreams…

      Like 0
  10. Kenneth Carney

    No need for a U-Haul if I had one of these. We could load up all our stuff,
    hook a towing dolly behind it for one of
    our cars, and get everything in one trip.
    Not sure what I’d do with it after we get
    moved, but I’m sure I’d think of something. Oh wait! Cadaver transport!

    Like 1
  11. Royal

    Looks like he has a second one sitting there too.

    Like 3
  12. Dave Mathers

    We bought a new 71 Citation Mini Liner and in 73 we were in Florida and I spotted those GMC motorhomes at a dealership in Orlando. It was love at first sight!! Don’t remember seeing any of these units.

    Like 4
  13. steve

    Yes yes yes! Roll up door and the best-est ever race car hauler! The air suspension could be modified to allow “kneeling” to keep the ramp angle low.
    As far as comparing it to a Sprinter? It’s about like saying a Fiero is a better sports car than a Crosley Hot Shot. Uhhh..what? Both have their uses and my Sprinter cannot do what this can ( total volume/low floor height) but gets 23+ MPG and has done over 27 mpg at 70 MPH across Texas and Oklahoma with a slight tail wind. These are not really any more comfortable (I have driven the motorhome version) and the 5 cylinder Sprinter is quicker and faster up to it’s governed limit of 80mph. The 6-8 mpg mileage would be offset IF you had a need for a super spiffy car hauler. A sprinter cannot do that. (I do haul cars with it but on an open trailer, sad to say)

    Like 4
  14. Eugene W.

    Leave it to GMC to come up with something innovative like this. I didn’t know a cargo van version of this fine motorhome was available. And, a 455 Olds V8 under the hood, and front wheel drive? I will take one of each, thank you!

    Like 4
  15. Johnny

    They can keep the transaxle. I had enough of them when I flipped my 64 Lemans . A off duty cop saw it all. He said when I jumped the hill and the back-end came down and the tires folded. The hit caused a tire to break seal and flipped it. Haven,t had a trans axle since.Won,t have another. This is a nice vehicle and some will have a use for it.Good luck.

    Like 0
    • ACZ

      You’re comparing apples to oranges. You need to learn what you are talking about.

      Like 8
    • R.Lee

      Playing dukes of hazard and it is the transaxle and tire failure’s fault. That makes allot of nonsense.

      Like 6
    • Driver J

      Johnny, you’re comparing ‘avocado’s to grapes’ with your transaxle story. I’m happy you made it but, the transaxle in your Pontiac LeMans is nothing like the FWD set up in this unit. It’s the same FWD system GM used in the Olds Toronado starting in 1966 & Cadillac El Dorado’s in 1987 & the Seville in 1981. Jumping hills in them, catching ‘air’ and bottoming out upon landing wouldn’t “Fold the tires” because the ‘set-up’ wasn’t of the “Swing-Axle” design that would contribute to “Folding the tires.” The front tires move up & down nearly vertically as in most front suspensions.

      Like 1
    • BR

      Pictures or it didn’t happen.

      Like 0
    • Phil D

      Johnny, I have no idea what your issue is with transaxles, but whatever happened is unlikely to have happened just because the vehicle utilized a transaxle, and this vehicle isn’t so equipped anyway.

      The Toronado/Eldorado/GMC Motorhome platform’s drivetrain was comprised of a GM Turbo-Hydramatic 425 transmission driving a ring and pinion-style differential. Both the THM425 and that particular differential were specialized pieces to accommodate front wheel drive, to be sure, but they weren’t a transaxle.

      Like 0
      • ACZ

        Phil, you’re right, but the 79 and 80 E cars used a 325 (3 speed) transmission and the 81 through 85 used a 325-4L, as they added an overdrive gear for fuel economy. The 425 was used on 78 and earlier Toronado and Eldorado.

        Like 1
      • ACZ

        As well as the motor homes. (sorry, hit post too quick)

        Like 1
  16. Phlathead Phil

    This thing reminds me of the T.V. Program
    “Lost in Space.”

    It came out of nowhere and quickly went back.

    Whew, dodged another one 🪐 🛸🛸🛸

    Like 1
  17. wardww

    The want is strong in this one young skywalker. This is a blank canvass that would make a very unique motorhome.

    Like 1
  18. SoIL

    If you could but a sxs in the back and basic sleep/kitchen in the middle it would be great for weekend camping and trail ride.

    Like 0
  19. Kenn

    Little_Cars = sad

    Like 0
    • Matt c

      That’s what people who dont have one or cant afford one say

      Like 3
  20. Max Nix

    Standard feature of GMC’s allowed rear airbags to lower for access. The wheel well bunks limit width of floorspace. If car is too wide, then could be ramped up. I’ve used my 26+1′ Transmode to haul motorcycles and to move.
    Great ride and low deck height.

    Like 1
  21. DayDreamBeliever DayDreamBeliever

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