International 7700 Offers More Capacity and a Smooth Ride

Sept. 28, 2010


The forward-set axle of new 7700 boosts legal payload in states with bridge-formula weight laws. Dumper and mixer shown here have 20,000-pound-capacity steer axles.
Tall, 12.25-inch frame rails, like these on this 7700 tractor, are strong and lighter in weight than the reinforced 10.125-inch rails available on the 7600 model.
The steel cab is spacious and tight, and its exterior and interior styling is automotive.
A Cat C13-430 nestles under the 7700's abbreviated hood. Smooth-riding three-stage spring pack uses four parabolic leafs separated by rubber bushings. The truck turned well, even with big wheels and tires.
An Ox steel body is part of the Integrated Dump Truck package, set up here on a 10-wheel 7700 chassis. This chrome-domed Truck Editor loves the 7000 Series' chromey nose.
Test Set


Truck: International 7700, conventional-cab Integrated Dump Truck, forward-set steer axle, BBC 107 in., GVW 66,000 lbs., w/12.25-in.-high frame rails and reinforced steel cab

Engine: Caterpillar C13 ACERT, 430 hp @ 2,100 rpm/445 hp @1,600 rpm, 1,550 lbs.-ft. @ 1,200 rpm

Transmission: Allison 4500RDSP 6-speed double-overdrive automatic

Front axle: 20,000-lb. Meritor MFS-20-133A on 3-stage (16/18/20,000-lb.) taperleaf springs, w/Sheppard (2)M-100/M-80 dual power steering

Rear axles: 46,000-lb. Meritor RT-46-160P w/4.89 ratio, on Hendrickson HMX-460-60 walking-beam suspension

Wheelbase: 205 inches

Brakes: Meritor S-cam w/Bendix ABS

Tires & wheels: Goodyear Unisteel 425/65R22.5 G286A front, 12R22.5 G244 rear, on Accuride polished aluminum discs

Fuel tank: One 70-gallon polished aluminum

Body and equipment: 16-ft. Ox steel

In this story:

What does it take to make a new truck model? To the casual eye, International's recently announced 7700 looks a lot like the existing 7600 Series on which it's based, because it does use the same cab, hood and power-train components. But the 7700 has features that improve its ride and boost its carrying capacity, meriting a 100-point uptick in nomenclature.

My first look at the new model was last fall, during a "Dig 'n Haul" event co-sponsored by International and Caterpillar at Cat's demonstration facility west of Peoria. Dealers and customers came in to sample various International trucks and tractors, all of course with Cat diesels (Cummins engines are actually standard in International's heavy-duty models).

I was underwhelmed with the new model until I drove one over rough ground and its front end didn't bounce. "Hey, this rides pretty nice," I remarked, and then paid more attention to the information supplied by Bill Sixsmith, the vocational segment marketing manager, on the 7700's new front suspension, as well as the other things.

Sixsmith and his colleagues formally introduced the 7700 in January at the World of Concrete show in Las Vegas. The 7700s I saw and drove in late September at Peoria were pre-production versions, as International's plant in Garland, Texas, began building this model last month.

Anyway, one of the 7700's distinguishing features is its forward-set steer axle, which makes it more suitable for bridge-formula states. The axle is centered 29.1 inches behind the bumper, compared to 39.9 inches on the axle-back 7600. Under many state weight laws, that 10.8 additional inches stretches the "bridge" between a truck's first and last axles, yielding 500 to 1,000 pounds more legal payload.

Another 400 pounds of capacity is available by using a lighter-weight frame. The 7700's rails are 12.25 inches high, like those on the 5000 Series. On the 7600, the rails are 10.125 inches high, and are sometimes fitted with inserts or outserts to achieve higher capacity. Such reinforcements shouldn't be needed on the 7700, keeping it lighter in weight but still muscular because its resisting bend-moment rating is 125 million inch-pounds.

A smooth ride

The 7700's new front suspension has a pair of multi-stage spring packs, each with four parabolic leafs separated by rubber bushings. Each leaf progressively takes up weight as the truck is loaded, and separating the leafs eliminates friction between them. Shock absorbers control rebound. It all makes for a smooth ride both on- and off-road.

Although each leaf pack is 50 inches long, there's enough room for it even with the axle-forward configuration. Thus, there'll be plenty of room under the axle-back 7600 to accommodate the new suspension, and that should happen in the not-too-distant future, Sixsmith said.

The 7600 now uses standard parabolic leaf springs, and while they are basically smooth acting, they're not nearly as smooth as the new design. Drive a 7600 and a 7700 over the same moguls and bumps, as I did at the Peoria event, and the difference is impressive. Any driver should be pleased with this advance.

The 10-wheel dumper I drove the most was an Integrated Dump Truck, part of the program that prepackages components, body and various equipment. For example, if you want a steel body, you'll get an Ox-built unit, though you can choose the type and length to go along with the wheelbase that's best for your operation. With this truck's 205-inch wheelbase, the body was a 16-footer.

You have other choices in the program, including the all-important engine and transmission, but far fewer than if you insist on spec'ing everything yourself. In return, you get quicker delivery, usually a reduced price, and a longer warranty. As they say, see your dealer for details.

There was a moderate amount of dirt in the body of this and other trucks at the event, so guests got an idea of how the trucks behaved under load. This 10-wheeler had a 430/445-hp C13 (it makes more power at about 1,600 rpm than at the 2,100-rpm redline) mated to a 6-speed Allison automatic, so there was plenty of power and driving it was not much work at all.

I drove several versions of the 7700 over gravel roads, briefly getting up to highway velocity in a few cases. But briefly doesn't tell it all, so Sixsmith let me take a truck out onto nearby Interstate 74 for some cruising. It rode as well out there as in the dirt, making the new front suspension feel like a real success.

As with other 7000-Series trucks, the steel cab of the 7700 is spacious and quiet, and appears to be tight and rugged for long life. Styling inside and out is what I call automotive, with curved lines in the dashboard; pickup-truck-style gauges and controls; and smooth, flowing lines in the nose and cab.

By the way, if I could, I'd bestow a styling award on International Truck for the chrome noses of its 7000 and 4000 Series. In an age when automobile stylists (and some truck types) have swarmed to the boring monochrome look, International's artists have splashed on the bright metal to make these trucks gleam. So did the folks at Sterling on their A Series. This is how vehicles should look, says this guy who grew up in the 1950s when Chrome was King (and who sports a chrome-domed head).

'Course, that chrome should stay polished for the sake of your company's image, but that's not hard with the 7000 Series' rather low nose (which not so incidently yields good forward visibility). Is the driver waiting in line to load or unload? Get him/her out there with a waxy rag to give the grill and bumper a once over. Is that too much to ask in return for giving the guy or gal something as nice to drive as a 7700?