Considering a '73 model

gerryg

gerryg

Active member
Jul 25, 2020
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Melbourne, Australia
Hi all,

I'm looking for a GMC and have found a '73 model. It would be my first motorhome.

Are there any disadvantages to buying an early coach rather than a later model? I've heard that there are some differences. Anything to watch for?

regards
Gerry
 
The later coaches have a number of improvements over the early coaches.

This is a great article on the history of the GMC Motorhome by Bill Bryant the GMC Motorhome Historian.

Off the top of my head....

-The dash heating and cooling system was improved several times to increase airflow.

-The seats of later models are made by Flexsteel with metal frames and springs. Early models were wood boxes with foam cushions.

-The quality of the cabinetry was improved from stapled drawers to real wood with dovetailed joints. The cabinet door construction was improved as well.

-The bases of the front seats was changed so they could swivel around to face the rear.

-The lower control arms were strengthened.

-The rear bogie pins were upgraded to a larger diameter pin.

-The early steel wheels are not rated for Radial Tires. Look for the word "Radial" or "R" stamped on the inside of the rim. Otherwise you cannot install radial tires on them.

-Vents were added to improve refrigerator operation.

-Rear suspension air controls were improved.

I'm sure there are others. If you want a model with a 455 and most of the improvements, look for an early 1977 model. Later 77's and all 78's came with a 403.
 
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Hi Gerry,

GMC Motorhomes were built in 3 two-year "eras" with each succeeding era improving on the preceding. I hope others will chip in more details, and I'm not an expert on all the changes for the third era, but here are some of the less desirable aspects of the first (73/74) era:

- Rear bogie pins undersized and front suspension less robust.
- Lower quality interiors built by Gemini subcontractor. In subsequent eras the interiors were either built in house or the coach was considered a TransMode, basically a shell that was upfit and sold by one of several third parties.
- Cockpit HVAC system barely functional (the second era was a little better and the third era was decent but not great).
- Side joints at beltline more prone to leaking.
- House window casings more prone to leaking.
- Lower-capacity house electrical system.

Note: In mid-77 the engine changed from 455 cu. in. to 403. Some prefer the 455, others don't care.

Depending on the specific coach you're looking at, many of these shortcomings may have been addressed by the previous owner(s). When I was searching for my coach a couple years ago, I focused on those from the second/third era. I would only have considered a first era coach if it were in exceptional condition or special in some other way, but I was willing to halfway across the country and wait as long as necessary to find the right one.

All of these coaches are a cut above just about anything else out there from an engineering perspective and from the strength of the owner community. The most important considerations aside from the era are condition and documented history (especially watch out for rusted frames and hacking by previous owners), expensive aftermarket upgrades like Alcoa wheels and ZipDee awnings, and paint (original is often in surprisingly good shape; many repaints are an abomination; new paint is $10k+).
 
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Thanks to the 3 of your for your replies. There are lots of things to consider there.

I should have said in the beginning that I'm in Australia. I think there are fewer than 30 GMCs in the country and so I'm in less of a position to be picky than those of you from the USA.

Nevertheless, I do want to purchase carefully.

Are there any 73 or 74 owners here that can tell me their experience?

thanks
Gerry
 
Try contacting Rob Mueller on the other forum. Rob is from Australia. PM him at this.

GMCforum: Login Form

For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.
gmc.mybirdfeeder.net

A long time member of GMC Groups. Haven't heard from him much lately but I think he could help you.
 
gerryg said:
I'm still considering the '73 coach that I found.

So, any '73 or '74 owners willing to set my mind at rest? Will I regret buying a '73?

regards
Gerry in Aus
Click to expand...
I own a 1973 26ft model. I do not have any concerns, I do not use it for racing. Have not been on any long trips but I have done a few 100+ mile trips.
 
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I think the only concerns I would have would be the lower control arms. Once those are reinforced they should be fine, they've probably been done already but something to check.

There are some differences in the windows but they still work and parts are available.

The rear bogie pins are a smaller diameter iirc, but again they can either be used as is, fixed if needed, or upgraded to the later, bigger pin.

And if it's still running the original points and condensor, small cap distributor, a good upgrade would be to move to the HEI large cap distributor.
 
FWIW, if you still have the original points and condenser distributor, an easy upgrade is the Pertronix 1181LS pointless ignition. It may be a better choice than the larger HEI distributor. It is an easy pull the points out, bolt the Pertronix in, set the timing, and never have to touch it again. Sending the distributor to Dick Patterson here in Canada is another option, but with shipping that distance might put you without a distributor for a considerable period of time. If you have the time, he is the GO-TO person for rebuilding and updating a distributor and/or your carburetor. JWIT
 
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Nothing wrong with a 73-74 per say, there were just upgrades for the other years. More than likely you'll be fixing the deficient areas anyway as the areas that were subpar will have been broken or replaced anyway or will need to be.
 
Gerry,
If you care to read this long tome it may be instructive regarding the '73 you're looking at.

My lovely wife and I have been using and loving an October/1973 coach since 1995. I have not had any major issues related to the year of manufacture. I don't know what your financial situation is or the span of your comfort zone, but both have an impact here. I paid $12K for my coach in '95 which in retrospect was probably high, but was all I could afford, yet there was nothing major wrong with it then and that situation remains. As a committed theatre person who thus condemned himself to a non-profit life, I do all my own work on the coach. Not as a hobby, but as a necessity.

I have dumped a lot of money in it over time, but on my schedule and on my whim. I started on running gear. Basic and cheap stuff first, timing chain, water pump, Pertronix ignition. It should be noted that I have an original 455 engine that had 140K on it when I purchased it. Skeptical of the brakes, I knew I'd be downshifting to slow down on long downhills so replaced the timing chain. Slight seepage on the water pump drove that replacement. By then I had discovered GMCMI and began to be familiar with marginal design decisions and common potential problems. Following their advice, but with no problems with the rear suspension, I worked with a machine shop and upgraded to JimK's larger bogie pins. I put Caspro shocks on it then as well. Around that time (2000) I replaced all the rubber belts, vacuum lines, fuel lines; what anyone prudent would do with a 30 year old vehicle. I had added, by this time, some 15K of my own miles on the vehicle.

Time passes, and with frequent use of the coach. A blown air bag caused me to order and install JimK's quad-bag suspension. Happy with that. Some time later, a potential trip to the mountains caused me to order and install JimK's six wheel disk brakes, master cylinder and sensitized booster. Again, not in response to a problem, but an incremental improvement to the coach in response to a potential need. Also happy with that. New Vair air pump, after rebuilding two original Dana's, buzz box replaced with modern, quiet charger, alloy wheels which expands access to available tires; all are incremental changes to a coach which has stranded me on the side of the road maybe three times in 25 years of ownership and frequent use.

There are documented benefits (posts above) in the post '75 coaches, which are favored by those lucky enough to afford them. But as they say in politics, there is more that unites us than divides us. That splendid collection of compromises which makes the GMC both a great driver as well as a comfortable sitter was there from the outset. As a long-time owner of an early coach I must note that most of my investments would benefit later coaches as well. When our financial status changed somewhat for the better awhile ago, I looked for a newer coach that I could afford. I was unsuccessful in my search by the time the need for disk brakes came up and that investment committed me to the '73 we bought in '95. It was an easy commitment to make.

So my advice is to evaluate the coach condition first, and weigh that well above year of manufacture. Sure I'd like a post '75 coach, but I don't suffer, and Wanabizo" ("He gets lost driving...", in Anishinabe Indian language) has become a beloved member of our family. YMMV
Doug
 
In the business at the time, the early GMCs were referred to a GMC-Gemini. This was to conform to the rear of the industry where there was a chassis and a coach builder that often had a very minimal relationship. While the entire interior was completely designed by GM with help from Home & Garden people and then full mock-up were tested and reviewed, the wood work was all done outside by the same people that had been doing the Travco and Cayo coaches for years already. Yes, the front seats do not swivel 180°, but they come far enough to work.

We have put over 70K on a 73 - 23. We have a curtain so the front HVAC is adequate. The bogie pins are still good, but the get a shot or three of grease every 1k mile. Yes, I put in the Pertronix 1181LS before the second turn-up and she has had a real CDI (Delta MKXb c1975) in there with them the whole time. (There were some things I knew about older engines before Chaumière.) I fit the rear brake "reaction arms" as soon as I could and love the brakes.

If you do buy it, get back to me about making the rear suspension work and be almost trouble free. It is a PITA issue, low cast but nothing really tricky to do.
The one thing I would do is plan to change out the lower control arms before about 120~150K. There was a factory directive to reinforce them, but it was inadequate in the long term.

A 73 will have plywood interior so it is less susceptible to water damage, but not immune by any means. It is also about 3~400# lighter than the particle board of the GM fit coaches.

the early coaches were also all copper plumbing. This is a two edged issue. I never bother with a regulator at an FHU park (unless the pressure is so high it actually causes problems). But it also means the clearing the potable for the winter has to be complete.

If you have any direct questions of an owner, get back to me.

Matt
 
I heard Holiday Rambler made the interiors, but haven't seen a confirmation.

The 73s got plywood instead of particle board?!? That's a great reason to own one right there!
 
Hi all,

I've been 'off the air' for a few weeks and have come back to a bunch more useful replies. I've read them and I thank you all! I am very grateful.

I think what you're telling me is if it is a good coach then I should not discount it because of the build year. I appreciate the help from the forum already and will certainly be here a lot if the purchase goes ahead.

I've just noticed that the floorpan of this particular coach is not in this list http://www.bdub.net/Floor_Plans.pdf. The coach has the Davo/bunk bed behind the driver as many do, but has swivel chairs on the passenger side with a small table between them. I've not seen this set-up before.

thanks again to you all
Gerry
 
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