GM's Midrange 4x4s Go Almost Anywhere
Chevy Kodiak and GMC Top Kick are nimble and quick on- or off-road.
Tom Berg
Equipment Editor
Yee-ha!" Just picture me at the wheel of GMC four-by, roaring up and over a hill, then bounding through ruts and only slowing down as we approach sharp turns in the dirt-and-gravel trail. This is the off-road course at General Motors' proving grounds outside of Milford, Mich., west of Detroit.
It was part of a show-and-tell for GM's C4500 and C5500 4x4s, which executives of the company's Fleet & Commercial operations hosted last fall. They had announced their factory-built, medium-duty 4x4s in March and the trucks went into production in July. This was trade-press writers' first chance at driving them.
GM is one of several builders that now offer factory assembly of midrange 4x4s. Executives note that this process saves time and money over upfitting at a modification center, which was the procedure for decades, and still is for heavier duty models, which sell in lower volumes.
It amounts to savings of about 40% over the usual upcharge for a midrange 4x4, according to Mike Eaves, a product planning manage. That's because a truck's front end needn't be pulled apart for installation of the Dana front-driving axle, New Venture Gear 2-speed transfer case, Spicer driveshaft and other parts. They're all installed as the chassis comes down the line at the plant in Flint, Mich.
Eaves was among the hosts at this day-long event, which allowed us to drive a variety of vehicles both off- and on-road. Travel on paved streets and roads showed the GMC TopKick and Chevrolet Kodiak four-wheel-drive models rode smoothly, especially when loaded near gross vehicle weight ratings.
Off-road they clawed their way up steep hills and through loose soil, just as you'd expect a good 4x4 to do. They can't conquer everything and you need to keep the tires on as good a footing as you can find.
One editor got a tie-rod end of his truck hung up on the end of a utility pole, and there it sat, its right-front wheel spinning uselessly and its rear wheels lacking enough traction in the loose sand to move the truck. A nudge from my truck pushed it off. Locking differentials would've helped, but they aren't available from the factory.
Otherwise, driving these Class 4, 5 and 6 trucks was easy. A wheel cut of up to 53 degrees means the truck is capable of tight turns and high maneuverability, which is helpful in any cramped situation. Making this possible is the front axle's setback position of 37 inches behind the bumper. This allows the steering gear to be mounted well forward and out of the way of the front wheel as it pivots toward the right. The power steering was precise, if slightly vague, as you'd expect with the front-driving axle.
Typical of modern part-time four-wheel-drive systems, a rotary switch on the dash allows on-the-fly shifting between 2 Hi and 4 Hi. Before going into or out of 4 Lo though, you have to stop and shift the transmission to Neutral. You also have to get out to lock or unlock the steer axle's manual hubs so the front wheels can get power.
There was plenty of power, whether the V-8 engine underhood was the standard gasoline-burning, 496-cubic-inch Vortec 8100 or the optional 403-cubic-inch Duramax 6600 diesel. The Duramax makes 210 or 300 hp and the Vortec puts out 225 or 325 hp, and I used 'em to move briskly over the course's rough sections, causing my passengers to hang on against the chassis' brisk bouncing. "Jeez, Berg!" some barked, but usually they were grinning.
Though these are hefty trucks with GVW ratings of 16,000 to 26,000 pounds, the C4500/5500s' agility helps them feel smaller. They accelerate well with those gutsy engines, either of which comes with an Allison 1000 5-speed automatic transmission. No manual tranny is available now, though one might come later, marketers said.
The autotranny's shifter is on the column, like in GM's pickups and vans. In fact, most interior parts, including a smallish steering wheel and many plastic panels, are from GM's G-series vans. All these things contribute to the small-truck sensation. The selector, as well as the gauges, switches and controls, are all easy to see and use.
Older GM midrange conventionals have pickup-based cabs. But the current C-series, introduced in summer of 2002 as '03 models, uses steel panels from G-vans. So the cabs, which Mike Eaves said are reinforced for medium-duty service, are wide and roomy, which is a plus for any truck whose driver is part of a two- or three-person crew.
The four-door Crew Cab version, introduced early last year, can be set up for as many as six people. Its rear doors are purpose-built for this application, with vertical leading edges that line up smartly with the trailing edges of the front doors. Ford does it this way for its SuperDuty models, which are GM's main competition.
A couple of other competitors use four front doors; the angled forward edges of those used as back doors look ungainly, and add extra length to their crew cabs. The GM Crew Cab has generous front and rear leg room and adds only 41 inches to the length of a two-door Regular cab. GM does not offer an Extended Cab in the C-series, though several competitors do in their comparable models.
While the GM doors look appropriate, they close with a "thung" rather than a solid "thunk," and the hinges squeaked in a couple of older C-series trucks I've driven. Keep your oil can handy and hope that squeaks are the extent of any problems.
While seated, a driver and passengers peer through a big, sharply sloped windshield. Its base is well ahead of the dashboard's rear edge, so cleaning the inside of the glass will require a long reach. The dashboard's top-facing surface is a big one and has shallow pockets to hold paperwork and such. Side windows are large and views forward and to the sides are good. Mirrors on unusual single-arm mounts provide good images of what's behind the truck.
The cab floor sits several inches higher than the doors' lower sills - another result of deriving the cab from the G-vans - and requires an extra short step up or down while getting in or out. A 4x4's higher stance demands a longer climb, which was awkward with the pre-production trucks but pretty good due to well-placed steps and handles on production models.
Guys and gals who work for landscapers, drillers, machinery servicers and public utilities should find the trucks easy to live with. So should recreational vehicle enthusiasts and others who take their trucks into rough terrain where extra traction is required. Like me, they'll also find them fun to run in the dirt.
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