It’s time to wrap up my recent obsession with GM’s ill-fated foray into IFS for big trucks. We covered the really big semi “crackerboxes” here, with their air-ride IFS, and the steel tilt-cab. But I’ve saved the best for last: a genuine curbside Chevy C80 to really show off its independent underpinnings. And what a gem it is; I fell in love with this dump truck, even if the operators of them didn’t so much at the time, causing GM to dump the IFS for a conventional beam front axle in 1963.
It was announced with great fanfare in 1960: “The biggest improvement in trucking in decades!” Independent torsion bar front suspensions across the line. It was classic GM of the era; the same year the Corvair arrived. Advanced engineering was the key to GM’s continued growth. The problem was that invariably, all these new technological miracles appeared before they were adequately developed. To revolutionize the truck field with IFS might have taken quite a few years of field testing. (CC’s post on the 1960 pickup IFS is here).
Here it is in great detail. It all made so much sense, at the time.
What could go wrong? Well, I’ve been unable to find exactly why GM backed away from this design within three years, but there’s several clues: A number of design changes for 1961 and 1962. These are some made in mid-year 1961.
And some more made for 1962:
There’s no doubt that weaknesses in the original design arose with the first year. There’s just a lot more to go wrong here, than the very tried and proven solid axle with leaf springs. Alignment issues, breakage and wear on components, tire wear from camber issues, and who knows what else.
Trucks live a hard life, especially so dump trucks that invariably have to go off-road into rough ground and with a heavy load. This will quickly reveal the weakest components.
Or just hauling a load of new Chevys.
Already in 1962, a heavy duty solid axle suspension was an option, although only on the tandem-axle M80 series, as pictured above.
This is a single axle C80, the highest capacity rated truck Chevy made except for the M80 tandems. Which is to say, it wasn’t really all that big of a truck (GVW 25,000 lbs), but a size that was popular with contractors and fleets due to its relatively low cost yet fairly high capacity.
Here it is, still on the road almost 60 years later. Obviously a few of these held up. The control arms on the larger trucks are solid forgings.
The other side. Looks to be a bit of mud in the mix. Those are some beefy looking ball joints on the steering gear.
Here we can see how the torsion bars are connected to the upper control arm.
The two-speed rear axle is suspended conventionally. I bet the sound emitting form that exhaust at full chat is something to hear.
I came very close to popping the hood on this one, to get a shot of the engine.
The standard engine for the C80 was the 348 “W” big block V8. With a four barrel carb, it was rated at 220 gross and 180 net hp. And yes, these numbers were trustworthy. The 348 was considerably revised in 1962, as it now shared cylinder heads and other changes with its bigger brother, the 409.
The 409 upped the ante a good bit, with 252 gross and 215 net hp. I’m pretty sure our feature truck has the 348, but I wish I knew for sure.
Here’s what it would have looked like if I had opened the hood.
The ’62 cab’s big change was the new simpler and flatter hood, dropping the controversial twin pods of the ’60-’61s. It still had the dog-leg windshield, and would until 1964.
If one didn’t know better, it would be easy to assume this was the cab of a pickup. There’s not much to give away that this was a serious truck. The Spicer five speed’s knob has gone missing. The button for the two speed axle is there though. As to the lever on the column, no, it’s not for a second transmission. I’m not exactly sure what it is; perhaps a trailer brake controller? Someone here will know.
This cab is familiar to me, as I spent a fair bit of time in a C60 flatbed that a construction firm I worked for in Iowa City had, along with some other trucks. It had the small block V8, and man did that little V8 rev its heart out, for a truck engine, especially compared to the Fords. Less displacement, but pushed hard, it would keep up with them.
The C80 did deserve its own instrument cluster, with an optional tach and air pressure gauge, if air brakes were specified.
The levers on the floor operate the dump bed, whose hydraulic pump is drive off a PTO from the transmission.
That’s what this truck is all about. And I sure could have used it back in the day when I was hauling lots of loads of excavation dirt and fill rock, with a rental truck. This would have been a fine alternative. Just the right size.
And I would have had that Jet Smooth Chevrolet ride too!
Postscript: I forgot to mention that this truck has either had a ’60-’61 grille swapped in, or it is a ’60-’61 with a newer hood. The ’62 grille had single headlamps.
More GM Truck IFS coverage: