Equipment Type

International TerraStar 4X4 Goes Off Road

International’s Class 4-5 truck gains new abilities but keeps its roominess and good ride qualities

April 30, 2013

“This thing’s a 4x4, so let’s see if I can get it stuck.” That was my remark as I tore onto the graded off-road course during this Navistar demo for press reporters and dealer sales people. Grading had left tall furrows of dirt like big, loose curbs on either side of the trail, and I steered into one, then another, to see if this TerraStar would bog down. Its wheels spun a bit, but we just kept on goin’. The fellow in the passenger seat, Mike Lamlech, Navistar’s vocational segment sales manager, was pleased.

Then I followed the course for a little while, dipping into pits our hosts had dug to show how the various International vocational trucks could enter and leave without dragging much of their noses or tails. Soon I ventured off the course again, this time stopping in a furrow in another vain attempt to hang it up. Nope—it chugged right out of the long pile. Lamlech was amused. 

Test Set

Truck: 2013 International TerraStar SFA (set-forward steer axle) 4x4, conventional cab, BBC 107 in., GVW 19,500 lb.

Engine: 6.8-liter (415 cu-in.) MaxxForce 7 V-8, EPA ’10 limits, 300 hp @ 2,600 rpm, 660 lb.-ft. @ 1,600 rpm

Transmission: Allison 1000 HS Optimized, close-ratio 5-speed overdrive, w/ 4th Generation electronic controls

Transfer case: Fabco TC-28 2-speed, gear-driven, 3,600 lb.-ft. capacity with electric shifting controls

Front-driving axle: Dana Spicer 70-273 single reduction, 8,000-lb. capacity, on 8,000-lb. parabolic, taper leafs

Rear axle: Dana Spicer S110 single reduction, 13,500-lb. capacity, w/ locking differential and 4.30 ratio, on 13,500-lb. Vari-Rate single leafs

Wheelbase: 128 inches 

Tires & wheels: 225/70R19.5 Goodyear G647 on polished aluminum (front and outer rear) and steel (inner rear) discs

Brakes: TRW 355 split system hydraulic, w/ 3-channel ABS

Fuel tank: Single 40-gallon rectangular steel

Body: 9-ft., 2-3-yd. Monroe MTE-Z steel dump

This was one of the nicer looking TerraStars I’ve seen, with its reddish-bronze paint and chrome grille and bumper. This model comes standard with a dull-black nose that only a Navistar executive or an International sales person could love. But whether in homely black or shiny chrome, grilles are molded in tough thermoplastic and help make TerraStars more than decent trucks. Four-wheel drive lets them vie for sales among users who must venture into rough terrain.

This little outing was back in September, when I drove several heavy and medium-duty trucks during one of Navistar’s annual “boot camps.” Like previous encampments, this one, west of Salt Lake City, was a training blitz and morale booster for dealer personnel, and a show-and-tell for the trade press. There was also a new company spirit: No longer would Navistar bad-mouth competitors; instead, at equipment displays, trainers showed what competitors did and explained why International’s approach was better.

Or just as good, in the case of selective catalytic reduction with urea injection, the path taken by other diesel builders and recently adopted by Navistar. It was forced to abandon its all-EGR approach with which it couldn’t quite reduce NOx levels in the engines’ exhaust enough to meet federal limits. Gone with Advanced Exhaust-Gas Recirculation were top executives’ claims that competitors’ SCR wouldn’t work and that the ammonia-carrying fluid would be toxic to drivers, which of course it wasn’t, and isn’t.

The MaxxForce 7 V-8 diesel in this truck was non-SCR and will remain so until fitted with urea injection in 2014. And if this diesel wasn’t quite clean enough to suit the feds, its exhaust sure smelled OK to me, and it was more than quick enough. Its 300 horses stormed through a 6-speed Allison 1000 automatic transmission that made off-road running a no-work affair, except for hanging on in the bumps. Long leaf springs fore and aft smoothed the ride pretty well, and previous trips in 2x4 TerraStars showed decent ride quality on paved roads. Rear air-ride is optional for sensitive cargoes.

Launched in 2010 with rear-wheel drive, the conventional-cab Class 4 and 5 TerraStar is International’s answer to Ford’s F-450/550 and Ram’s 4500/5500. International’s go-almost-anywhere product was supposed to be out in early 2011, but problems with suppliers delayed it, executives said. That was just as well, because the truck now has a gear-driven transfer case instead of one with chain drive, and its chosen front-driving axle is stronger. Navistar featured this truck at the recent Work Truck Show in Indianapolis, where execs touted its superiority over the others.

Chief among the TerraStar’s attributes, they said, is its commercial-grade design. Its galvanized high-strength steel cab was taken directly from the larger DuraStar, and it has a huck-bolted frame with 80,000-psi main rails instead of uprated pickup pieces. The cab is 30 percent larger than competitors’, which means more room for driver and passengers, and has bigger windows that provide 38 percent better outward visibility. Wide exterior steps make for easy entry and exiting, and they’re available in aluminum.

TerraStar’s tilting hood-and-fender assembly makes service and repairs on the engine and its accessories far easier than delving into the comparatively small opening left by a pop-up alligator hood used on competitors’ trucks. In the compartment is Navistar’s 6.8-liter V-8 diesel with a cylinder block made of compacted graphite iron, said to be stronger but no heavier than regular cast iron. Its low-end output of 660 lb.-ft. is competitive with Ford and Ram engines in these weight classes.

An Allison automatic with Optimized shifting efficiently delivers power. Allison’s 1000 series includes a Park position, which drivers of light-medium trucks are accustomed to. Driving the truck was as easy as piloting a pickup, but the roomier cab with its no-frills interior trim reminded me that this was indeed a commercial truck.

The shift selector was a T-handled lever on the floor, and rocker switches on the dash controlled the Dana front-driving axle and Fabco transfer case, the latter with High and Low ranges. I switched into Low just to see how it felt, and sped up to see where the engine would top out. That was about 35 mph. In High range on the highway, the truck would probably do 80 mph or more, getting your crews to their jobs more quickly than you might like, but you could inquire into setting the electronic road-speed limiter lower.

Like other Internationals, the TerraStar uses the Diamond Logic electrical system that makes body installation and operational settings a plug-and-play exercise, as Navistar people are wont to say. Switches are programmable, and although this truck didn’t have many, the possibilities are intriguing. Floor-mounted controls had been installed to run the dump body, and we can hope that they plugged into the truck’s wiring instead of being cut-and-spliced in. Navistar and other builders with similar multiplexed wiring want body installers to use connectors so circuits aren’t damaged. 

My off-roading in this TerraStar saw me take it through the graded course twice—or was it three times. I tested the patience of other guys who waited to drive it, but my apologies gained forgiveness. We were all just doing our jobs, which with this truck was a delight.

 
 

Comments on: "International TerraStar 4X4 Goes Off Road"

Subscribe Today

Enter your email address here to be automatically subscribed to our daily newsletter!

CE-Field Test,CE-2013,CE-Trucking & Hauling,CE-Medium-Duty Trucks, Classes 4 - 6, 14,001 to 26,000 GVW
Email Subscriptions