1977 GMC "Jimmy Mini"

I too noticed the THM-400 with the vacuum modulator on the front right side. The THM-350 had it on the rear left side. Memories.

j-d wrote:
M40 was THM-400 offered 1976-88. The "40" and "400" appear coincidental. The THM-350 was M38 and M39 was a 5-speed manual.
Dual exhaust...That wasn't factory.
Roof - WAY too far gone. You're right in walking away.
Too bad, it could have been a very interesting, an good driving, RV!

x10 on the roof! My memory could be failing me, but I thought GM didn't use any 5 speed manuals in their full size trucks until '88. Prior to that I thought it was a "granny low" 4 speed.

Thanks for the clarification on the tranny j-d. Yes, we have kind of a soft spot for the older, cooler stuff that isn't so common anymore. We'll keep looking for something that we'll replace our new 2013 TT with; it doesn't fit our lifestyle as expected when we retired. We're more into old-school cool and shorter trips (both in distance and calendar) and something easy to get the kids into, for when they can join. Hmmmm, maybe an old Winnebago Class A? Or a GMC Class A. OMGosh what am I doing!

M40 was THM-400 offered 1976-88. The "40" and "400" appear coincidental. The THM-350 was M38 and M39 was a 5-speed manual.
Dual exhaust...That wasn't factory.
Roof - WAY too far gone. You're right in walking away.
Too bad, it could have been a very interesting, an good driving, RV!

So we went back and took a closer look at the "Jimmy Mini". We decided against it, for a few reasons, mostly because there was too much evidence of a past leaky roof in the upper wall cabinets and in the cab-over bunk.

But since we had been discussing this subject, I thought I would post some info so others might find this online in the future.

At least THIS "Jimmy Mini" was built by Coachman Industries. I found this on the driver door pillar.



This also indicates which rear axle is used if you know what to look for, as the GAWR is 7200 lbs.

Here's a view of it from behind.



And gives the chassis info at 10,500 lbs for the GVWR. Good info for those who may need it as these things are not typically found in "sale info and pictures".

Another on the door pillar.



Here's a roof shot or two, another item not typically found in online sale posts.





The underhood sticker shows it is a 400 CID V8 and the Turbo-Hydra tranny, probably a TH350 as I've heard the TH400 is usually found behind the big-blocks. But I don't know that for a fact.



More under chassis shots for somebody who knows what they need to look for.

Great info!

So I can probably assume the 23' (I stepped off 25' bumper to bumper) 1977 GMC Jimmy Mini I'm looking at is a G30 third generation van cab (saw the same thing on an X-Files Ambulance rerun just last night :) ) on a rail frame chassis rated at 12,300 GVWR, and that it's NOT likely a P30, which was apparently a larger frame chassis, not a later frame chassis (as I said earlier about it maybe being a fourth generation).

Thanks so much!

Still haven't gone back. Will do that probably next few days between weather and other chores.

1977 G-30 should be a third generation G-series van cab mounted on a rail frame with dual rear wheels (the actual van was still a unibody). GM also sold this as a bare chassis. I've seen smaller 80's Class A's on a 12,300 GVWR G-30 chassis, and there were G-20 and G-30 bare chassis also spec'd for panel vans.

All the G-30 C motorhomes I've come across have been either 350 or 454 V-8s. I don't know if GM ever offered the 6.2 and 6.5 Detroit diesels for cab-chassis.

G-series is not quite the same as the larger P-series chassis, although there is a size overlap and lots of components in common. P-series came in heavier GVWRs and more different lengths. Also, the motorhome P-chassis was not really the same as the step-van P-chassis, the motorhome got different frame rails and suspension components.

All three major auto companies went through phases of branding recreational vehicles (including conversion vans) made by third parties and for sale through their dealers. AFAIK the only motorhome actually manufactured by General Motors was the one developed and built by GMC Truck and Coach, the front-drive tandem axle Class A.

I know Dodge sold some Class A's built by Frank Industries (became Travco) as Dodge motorhomes and sold third-party camper conversions on the Sportsman van. Dodge may have sold a Dodge-branded C, but I've not seen an example.

Ford sold camper conversions on the first generation Econoline van, these being installed by Sportsmobile at Ford's Lorain assembly plant.

We're making progress ;).

Yeah I saw that YouTube video. VERY same, except that one looks a bit rougher, or maybe a lot rougher!

On Nadaguides I found Jubilee was 1985-1988 so that's too new. I HALF think P10/20/30 is associated with the GM Express van and style that replaced the Vandura era G10/20/30 in about 1996? But that is an assumption unverified.

I'm not interested in manufacturer due to dealer and parts help, just the fun of knowing history of my things. :)

Interesting to hear one person's "Jimmy Mini" was on a Dodge chassis! My assumption was Jimmy meant GMC just like their version of Blazer. Oh! But the front house cab-over says GMC! And at 1977, these were being built at the same time as the Class A factory unit. But I seriously doubt GM would have done a Class C in their factory by this stage of their game. It had to be contracted out to an RV builder.

We had a Minnie Winnie by Jamee in the past. It was much shorter, had a Chevy, maybe about a 79-84? I think it had the longer front nosed hood. It used the 400 CID V8. But it was kind of rough. Even so it handled those dirt roads nice.

I like the idea of the old school mechanics, so much easier to work on for a do-it-yourselfer. And keeping it cheap for the kids to mostly use (and get out with us) while we do our thing in Lil' Queeny (TC forum).

I may learn more today when I go see the title and other paperwork. I'll keep you posted.

I am straining some old neurons here, but as I recall they were built on a GM P30 chassis and the house was the product of a company (long gone) called Jubilee. It really doesn't matter as long as the house hasn't leaked and damaged the structure. Even if the company was still in business, they would/could not be much help.

Good Luck

Matt

Viator is one of the ones with the typical seamed front overhang. One I saw a pic of had a molded cap. Probably different years. The gOOgle image collection wasn't real well done. One "Jimmy Mini" was on Dodge and another on Ford. Oh well.
I hope D has/had a successful voyage.