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[Brakes] [Mirrors] [Thermasan] [Black List] [Sandy's GMC Summaries] [Tires] [GMC Motorhomes Intl]

[] [Tail Light Update] [Interior of Walls] [Fantastic Vents] [Hose Vault] [TrueCharge 40+ Charger]

[Ceiling Structure Pictures] [Cabinets] [Window Detail] [Door Switch] [A/C Mounting] [Rebuilding the Rear Floor]

[Range Hood] [Claude's Flares] [Arch's Leak Pictures] [Irene's Insulation] [Thomas Compressor Update]

[Rear Permanent Bed With Storage] [Manny's Aux Outside Shower] [Electrical FAQ] [Living on 12V]

 [Bruce Tara’s Lift Up Bed Design] [Russ Harm’s EFI Info] [Erv Troyer’s AutoCAD Drawings] [Bruce Tara’s AutoCAD drawings]

GMC Motorhome Web Pages


Why We Bought One

In 1997 I decided that the amount of travel time that we spent visiting clients, attending tradeshows, and interviewing corporate executives was hurting business and running up our expenses unnecessarily. And, by spending so much time traveling, our ability to have a vacation or satisfy our client base suffered. So, we started looking for a motor home that was small enough to navigate the streets where we often travel.

For many modern motor homes, small meant cramped. And big enough inside was too big outside. We then discovered the GMC motor home built in the mid 1970s. In March of 1998 we bought a 1976 Palm Beach model and began rebuilding it to ensure mechanical reliability. The summer of 1998 involved 8,000 driving miles in our "new" classic motor home. We have since added a 1977 Royale rear dry bath coach to our "fleet." It was purchased in pieces - a body with no drive train, and later the drive train. So, we took one wreck and used the parts from a burned unit to make one whole GMC. Total GMCs consumed – three VIN numbers. In the Spring of 2001 we added a 73 23’ coach. The coach was a rescue from a wrecking yard. Emery Stora was visiting and helped me get the beast started. New freeze plugs and many new parts make me believe that I may have gotten a good deal. BUT, I still have registration issues to deal with. And some damage caused by vandals.

Interested in Classic GMC motor homes? Take a look at Patrick Flowers' GMC site. Patrick also runs the GMCnet mail list. You can get information about the list at his GMC web site.


Mirror Upgrade

The stock mirrors left something to be desired. My wife and I are different heights and need to have mirrors repositioned when we change drivers. ON the GMC this is a major pain because someone has to stand outside to move the mirrors. Also, I found the stock mirrors to lack coverage in some key spots. We upgraded to Ramco remote controlled mirrors. See what they look like, and some of our minor challenges during installation.


Brake Upgrades

The original brakes on the GMC are disk front and drum rear. Our brakes work fine for the driving that we do. But, some owners travel in more mountainous terrain where the brakes heat up and are subject to fading. Disk conversion kits are available to modernize the brake systems. Manny Trovao's disk brake conversion pictures.



GMC offered an option for the motor home that incinerated waste from the holding tank when conditions were right. The exhaust provided the heat and the exhaust pipe flushed the ash out the tail pipe. Click for one of Thermasan's patents that describes this system. My goal is to find modern replacement parts for this simple system so that they can be kept working. Thermasan was part of Thetford Industries but closed in 1980 due to the reduced demand for RVs. All of the people who knew about the Thermasan system have left the company. Thanks to folks on the GMCnet I am gradually adding information to my files - soon to be sufficient to re-create the system.


Roger Black's Help List

Encouraging like-minded people to share information is one of the great benefits of the Internet. Roger Black's questions and suggestions that members of the GMC Mail List who are willing to assist other GMC owners when they have trouble while travelling identify themselves. The interaction on the Mail List led to the creation of an online GMC Assist List. The document is also available in WORD version 6.0, RTF and PDF.


GMC Mail List Summarized

Sandy Davis has created a series of edited documents that cover a variety of GMC topics discussed on the mail list. The list is impressive!


GMC Motor Homes International

Take a look at it's another good source for GMC specific information. GMC MOTORHOMES INTERNATIONAL was formed July 21, 1982, as a chapter of FMCA, to provide the exchange of technical and non-technical information at semi-annual conventions and in a quarterly newsletter to help keep the classic GMC Motorhome On-The-Road.


GMCnet at Casa de Fruta

The GMC Western States rally at Casa de Fruta had some really great weather - and nice looking coaches. GMCnet was represented by campers Al Chernoff, Manny Travao, Chuck Will, and Henry&Irene Davis who had planned to camp but a business emergency called Henry out of town. You can see (left to right - Manny, Al, Chuck, and Henry) a picture of the four taken with Manny's digital camera. Manny was busy with the camera, getting lots of great pictures. One GMC was a stretch with an interesting window (closeup of curb side). And here's three views of GMCs lined up 1, 2, 3.



What tire to choose for your GMC coach? Like many others, Tom Warner bought a "new old" coach without having other GMC owners to talk with. While GMC recalled load range D tires on the GMC, many coaches retain the load range D tire specification sticker in the glove box. Tom had blow outs. Here's what he's learned about tire selection and the difference between car and truck tires.


Tail Light Update

Want more brake light to be visible when you step on the brakes? Or maybe you want to update the brake light assembly to a more modern look. Here's my experiences in updating the tail light lens assemblies with a modern GMC version. I'm not done yet, but well on my way. So far, I have about 30 minutes total into the job - most of it missing the obvious. Probably less than one hour to go.


Interior Wall Structure

If you're curious about how the aluminum structure inside the walls of your GMC, take a look here. NOTE: these are from my 1976 Palm Beach and Arch's coach, other models may differ.

Curb side dinette area

Driver's side pictures from Arch

Cab Pictures from Arch


Fantastic Vents

The rear bedroom is much more comfortable with a variable speed vent with choice of blowing air in or out. I chose the automatic vent because I can set a temperature at which the vent opens and runs. My vent also has a rain sensor - leave the vent in auto and it will close when rain hits the sensor. CAUTION: the vent isn't a perfect rain sensor. You will get different amounts of rain inside the coach depending on ho hard it's raining and the coach orientation with respect to the rain. I had to cut the vent trim down in order to make it flush with the ceiling.

Inside the bathroom - the vent opens up the feeling of the small bath and lets plenty of light in during the day. The vent gets rid of moisture rapidly. For the bath I chose a manual vent - if rain gets in the bathroom it's OK because there's a floor drain. The vent matches pretty well - but the trim had to be cut down to match the ceiling.


Hose Vault


I switched to a macerator pump - a BIG improvement in dumping the holding tank. With the macerator I can pump the black tank contents about as far as I need. But with the macerator you do need garden hose. My solution was to remove the 3' section of PVC used to hold the collapsible 3" hose and replace it with a piece almost 6' long. I glued a cap to one end and a housing for a screw cap to the other end. Inside are 4 or 5 pieces of garden hose that I cut into 5'6" pieces and added fittings to the cut ends. Four pieces fit easily, and 5 will fit with some careful placement. The four pieces of hose will let me dump 22' away - which is long enough to reach from my coach to an inside toilet at the warehouse. I carry spare hose washers in the coach sot hat I can ensure tight fittings.


Battery Charger/Converter

Getting energy back into house batteries can be a hassle for people boondocking. Here's our charging solution for use with shore power or Gensets. Later we'll look into sufficient solar power to drive our computer and a radio - and maybe one light. We calculate that to be 120 watts (about 2.5 Siemens premium panels).


Window Detail

Removing the window trim corner pieces is a piece of cake - two screws and they're off. But he center sections require more work. Here's a series of pictures that show the extrusion detail for holding on the trim.


Door Switch

My switch is getting a bit "rough around the edges." Here's some pictures.


Ceiling Structure

One of the most often asked questions - what does the structure under my headliner look like? Well, it mostly looks like the diagram in the GMC manual. But, there are important details not shown in the books. Here's a series of pictures that show much of the ceiling structure.


Air Conditioner Mounting

The original coach A/C mounting from inside the coach.


Rebuilding the Rear Floor

Have you ever had one of those days? My new headliner didn't fit right. I forgot to order some parts. And the minor remodel in the rear of our Palm Beach has turned into the construction project from hell.


Range Hood and Vent

Cooking means running the range hood. SO it's good if you have one. Here's what we did trying to salvage the old range hood.


Claude's Flares

GMCer Claude Brousson designed and manufactured flares for his GMC. It's a lot of work to make molds and get the fiberglass just right. So, Claude is making these flares available. Here's some more information and pictures.


Arch's Leak Pictures

Motorhomes leak. And the GMC is no exception. Finding those leaks can be a frustrating job. Here Arch shows pictures of what the stains look like and where the leaks were found in his coach. Roof vents, water fill, drip rail and the fresh water tank are a few of the more common sources.


Irene's Insulation

My wife and I divide tasks up according to who wants to do which piece. Irene's an accomplished plumber (25 years of taking care of the house when I was traveling), carpenter and seamstress. She's taken the Shelter Institute course on post and beam construction and has a lot of practical experience. On the other hand, she doesn't like electrical work. And the engine/transmission is interesting but not her primary love. (I should also mention that she's the only woman that I've known who achieved a perfect score on her mechanical aptitude tests, so she could do it if she wanted to. She repaired our car a number of times when I was at work - including replacing the radiator and water pump) So, we have a pretty good division of labor from the start.

From her home construction experience, Irene is a fanatic about insulation. Last year she made insulating "black out" curtains from Reflectix insulation material. Now she's buttoning our coach up so the A/C and heater do the job they were intended for. Here's some of what she's doing to improve the GMC's insulation.



Here's some information on how the cabinets are installed. Taking them down is definitely easier than reinstalling them.


Thomas Compressor Update

Air compressors get worn out or sometimes don't meet GMC owner's expectations. Scott Nehoda is in the process (July 99) of negotiating a volume purchase for the Thomas compressor to replace and upgrade the old Dana and other compressors used on the coaches. Dave Mumert has provided schematics for employing the Thomas compressor in both a vacuum pump and compressor configuration.


Rear Permanent Bed

Say what??? You don't like sleeping on the converta-bed side facing settees? You can add a permanent bed in the rear that allows you to use a real mattress. One caution though - you'll need to have a mattress company eliminate the side steel or as we have done, have the company remove a short section of steel in the middle of the mattress. That allows you to fold the mattress to get it in the back.

More storage is always welcome in the GMC. When you build in a permanent bed, you gain at least the space under the bed as storage. We also built an 11 1/2" deep under the bed storage that runs 74" from side to side and is 44" deep. On top of that, by eliminating the bedding locker, I gained another 42"x11"x11 1/2" box on the curb side. This box alone allows me to eliminate the dinette cabinet and open up the GMC living space.

How deep you build the storage area will determine how much of a leap it is into bed. By the time I put the mattress on my bed, the mattress top comes up almost to the windows. You may want a lower bed. If so, adjust your depth accordingly.


Aux Outside Shower

Manny installed a nice shower outside so that you can rinse off before going into the RV. The Unit closed and open.


GMC Electrical FAQ

I have assembled a series of questions and answers to a variety of GMC electric questions - mostly the 12V house systems. There is an online version, WORD format, and PDF.


Living on 12 Volts – A GMC Perspective

A Powerpoint presentation that I gave at GMC Western States and PDF version.