Medium-duty chassis family added by GM

GENERAL Motors' presentation at the NTEA's Truck Product Conference in Dearborn, Michigan, focused on the all-new program for the 2003 model year featuring the GMC TopKick and Chevrolet Kodiak.

The C4500 replaces the 3500HD, the C5500 is a new entry, the C6500 replaces the former C6, the C7500 and C8500 replace the former C7, and the C8500 tandem replaces the former C7 tandem.

GM's Mike Eaves said that with the new family of medium-duty, an all-new cab design provides improved maneuverability, visibility, comfort, convenience, and an up-level appearance for the C4500/5500.

The wide range of product includes a regular cab, cutaway, motorhome (for the first time), and school bus/shuttle bus above 16,000 lb, plus a crew cab by the end of the year.

The new/upgraded powertrains: Duramax 6600 (210 and 300 hp with 520 lb/ft of torque; Duramax 7800, an inline six-cylinder engine (200-275 hp up to 860 lb/ft of torque); Caterpillar 3126E (207-300 hp up to 860 lb/ft of torque); and Vortec 8100 MD Gas (LEV compliant, with alternative fuel capability).

There are new frame designs. In the C4/C5, it's a straight-frame rail chassis, with 80,000 psi material in 6 and 8 mm thickness for cab models and L reinforcement availability. The 50,000 psi frame is for cutaways: motorhomes, commercial cutaways, school buses, and shuttle buses.

In C6/7/8, frame rails are in 50,000/80,000/110,000 materials, with L reinforcement availability and cross members that retain an eight-fastener attachment.

New front-axle designs for the C4500/C5500 are 6,250 and 7,000 lb and 8,000-16,000 lb for C6500/7500/8500. Eaves said new steering systems contribute to improved ride and handling.

Rear axles are 11,000 lb for the C4500 and 13,500 lb for the C5500. For C6500/7500/8500, the single axle is 15,000-26,000 lb and tandem axle 34,000-45,000 lb.

Suspensions feature front taper leaf (multileaf optional select ratings) and rear multileaf standard, with taper leaf and single-axle air systems available.

New hydraulic brake

New hydraulic brake systems available: Hydroboost two-piston design on the C4500, 7,000 axle Hydromax four-piston front on C4500/5500, and Hydromax four-piston front and rear on the C6500/7500. All models are using ABS, with G80 Limited slip differentials on the C4500/5500 and driver-controlled differential locks on the C6500/7500/8500.

Since introducing the C4500, the 16,000-lb model has changed to a front axle rated at 6250 lb (from 6000 lb), with CAs of 60, 80, and 108 inches, and a standard 7000-lb front suspension.

The 16,500 GVW model is a new addition, with a 7000-lb front axle, CAs of 60, 84, 108, and 120 inches, and minimum GVWR required with the wrecker (YW2) and snow plow (ANQ) packages.

Changes to the C6500/7500/8500 include: a frame-mounted vertical exhaust (NPV), with right-side vertical exhaust and muffler/converter, available with the Cat 3126E engine in the first quarter of 2003; fixed grille (GRW), available in October 2003; and 23,000 rear air suspension on a 4×2 tractor in the first quarter of 2003.

RediSpecs have been developed for all models, providing easier ordering and stocking, reduced delivery times, better relations between body companies and GM dealers, and more dealer/salesperson involvement.

“We know we compete at the dealership with a lot of other products,” Eaves said, “and this is going to help us market those products more easily.”


On the topic of 2002 emission changes, Eaves said, “The good news is there really is not much change for General Motors.” Cat's 3126 engine will have a new electronic fuel pump, the 190 hp/420 lb/ft option has been canceled, and the fully compliant engine will use ACERT technology for the 2004 model year. Eaves said the price increase of about $250 will be the only one that will be made on diesel-engine options until 2004. He said the Duramax 6600 and 7800 remained unchanged, and the next emission change will be January 2004.

He stressed that those who want a PTO must order that option on all their trucks. If “PTX” appears on the order, that means there is no PTO included.

Circuit protection has been upgraded. On the C6500/7500/8500, it provides circuit-breaker protection where possible in areas such as lighting, heater/AC control, gauges, accessory, radio/chime, and fuel. On the C4500/5500, it incorporates fuses in all areas rather than circuit breakers. Eaves said GM has a “much more robust electrical system” now that the number of total devices has been increased from 39 to 56.

He said trailer wiring on the C4500/5500 includes a seven-way connector with 30-amp electric brake, park lamp, right/left/stop turn, backup, ground, and auxiliary electric brake (dark blue, blunt cut in I/P harness). On the C6500/7500, it includes 40-amp ABS, park lamp, right/left turn, brake lamp, marker lamp, and ground.

On body builder upfit, he recommended using the GM-provided electrical interface, which includes dedicated body builder power supply, body builder circuits, and grounding block.

“We know some people go into electrical systems on their own,” he said. “That is perhaps a recipe for disaster down the road.”

New crew cab

Discussing the new crew cab, he said the BBC dimension is 146", which adds 41" over the regular cab. The compact overall BBC maintains superior maneuverability. Carrying five or six passengers, it has a bench rear seat with fold-down backrest, full cab-length steps for easy entry and exit, and more roominess with the compact overall BBC dimension.

“When you see this cab, I think you'll appreciate the roominess in the back of the cab,” he said. “We have over five inches more leg room compared to our direct competitor.”

The C4500 crew cab has a 16,500 GVW (6,000 front axle, 11,000 rear axle) and 17,500 GVW (7,000 front axle, 13,500 rear axle), and comes in CAs of 60, 84, and 108 inches. The C5500 comes in 18,000 and 19,500 GVW (7,000 front axle, 13,500 rear axle), and comes in CAs of 60, 84, 108, 120, and 126.

A 10,000-lb axle is standard on the C6500/7500, with front axles of 12,000, 14,600, and 16,000 and all rear axle available (15,000-26,000 single axle, 34,000-45,000 tandem axle), and CAs of 84, 108, 120, 238, and 150 inches.

Eaves said the crew cab shares many components with a regular cab, but has new rear doors with a symmetrical design and rear doors that include cup holders and speakers (with radio). All fuel tank options are available.

New options: deep tinted rear glass, delete rear seat, delete rear seat and belts, delete rear seat, belts, and floor studs, heated rear window, and rear heater located under rear seat.

The new crew cab will be available in December, with a ramp-up schedule through February. Target volume is 5,500 per year. Target customers: tow and recovery, trailer/motorhome haulers, municipal and state governments, utility and telecommunication, fire and rescue, landscape and tree maintenance, contractors, railroads, and moving services.

He said production of the 2002 model year T-Series ceased in June, and inventory is available from GMC, Chevrolet, and Isuzu dealers. Revised T-Series will be produced in Flint, Michigan. The product range and appearance will be similar, with high commonality with the C6500/7500/8500, and availability in the second quarter of 2003.

Express and Savana

Mike Johnson, assistant marketing manager for full-size vans, began his presentation with a quote from Truck Trends Magazine: “The new Express and Savana launch with segment-busting features.”

GM's slogan: “Strong, Smart, Surprising.”

Johnson said the vans are strong because they include Vortec Gen III engines (which are used in the Sierra and Silverado trucks), independent front suspension, two wheelbase lengths, and an exclusive box-frame design, and four-wheel disc brakes and 16" wheels that are standard.

He said they are smart because of an advanced Class II electrical system that includes oil-life monitor, battery run-down protection, delayed accessory power, and lockout protection, along with tow/haul switch, air-filter monitor, standard ABS, and daytime running lamps.

He said they are surprising because they include a left-hand door, all-wheel drive (which he called an industry first), pro/access panels, OnStar (on conversion and passenger vans), truck-styling cues, outstanding ride and handling, and protective halo.

He said the left-hand door is “an industry-first innovation”, with a 60/40 left-hand door that is available on 135' WB cargo, conversion, and passenger models. The left-hand door mirrors the right-hand door, opening the market to “unique upfit options.”

The Savana Pro and Express Access option package includes left- and right-side remote release access panels, power locks and windows, and optional interior lighting package. It is available on all 135" wheelbase cargo vans, and in all GVWs.

All Wheel Drive is a full-size van exclusive, and is available on both cargo and conversion passenger models with 135" wheelbases and up to 7300 GVW.

He said four-wheel power disc brakes are similar in design to those of the Silverado and Sierra, and are standard on all GVWs. They provide shorter stopping distances and longer brake lift — 40,000 miles on light-duty models.

The all-new interior includes front and rear seating, instrument panel and floor console, improved HVAC systems, OnStar (available on passenger and conversion vans), trim panels and headliner, and second-row belt-to-belt restraints. It meets new safety regulations, with dual-level bag inflators and seat-belt pretensioners (both in light duty only), plus manual air bag suppression switch on vans over 8600 GVW.

The Class II electrical system includes bussed electrical center design (under hood and driver seat), delayed interior lighting, lockout protection, delayed accessory power, and battery run-down protection.

Full-size truck update

Dan Tigges gave GM's full-size truck update, saying the 2003 mid-cycle enhancement includes the front-end appearance and new mirrors. On the interior, there is new multiplexing (dual zone climate control, a new family of radios, and enhanced Driver Information Center) along with new seats, new switches, and a new center console.

The Silverado/Sierra package includes optional base trim mirrors: DF2 ($70 manual extendable camper mirrors, with right side dual segment glass); 9G1 ($109 DF2 with right full convex glass and left dual segment mirror); DG5 ($115 West Coast mirrors on chassis cabs only); 9F7 (spring-loaded West Coast mirror, $125 on all 2500HD and 3500 models, with the 9N8 adding 6” spot mirror on each side at $50). There is also an optional uplevel trim mirror: DPF ($238 for new power extendable mirrors, with power extending to 106" total width, power adjustment, heat, and in-glass signals).

The VYU snow plow prep package includes: 145-amp generator standard with VYU; package model availability is a carryover; availability on all four-wheel-drive models except 1500 extended cabs and 1500HD crew cab; and the same engine restrictions with longer wheelbases.

The YF2 ambulance package has a stop order that is being lifted, with trial runs being scheduled and regular production that began in November.

Tigges on emissions: the Vortec 4300 with automatic transmission and Duramax Diesel 6600 can be ordered with Clean Fuel Fleet certification.

On alternative fuels: E-85 Ethanol Flex Fuel is available with Vortec 5300 (L59) using SEO 5E5 (the range for E85/gasoline with a 34-gallon tank is 327-393 miles/425-556 miles, and with a 26-gallon tank is 255-306 miles/332-434 miles).

He said the Compressed Natural Gas Bi-fuel (KL6) and Gaseous Fuel Ready (KL5) go with the Vortec 6000 engine. KL5 and KL6 are available at 8500 or 9200 lb GVW on regular and extended cab pickups and 9200 lb on four-wheel-drive crew cab pickups. KL6 is available on 2500HD (9200 lb GVW) regular cab box delete models (C/K 25903).

In his production update, he said a third shift was added at the Pontiac East Assembly, which will mean 80,000 additional units annually, and 10,000 additional in the fourth quarter of this year. They will begin producing the Vortec 4300 V6 in January.

Models C36453 and K36453 (extended cab chassis cab with 84" cab-to-axle) have been dropped from the portfolio due to low volume. All other 3600 chassis cabs have been moved to Pontiac East. Crew cab production will be increased at Flint.

As for distribution issues, he said the Duramax Diesel model year availability for full-size pickups is improving. In May 2001, there were under 50,000 units. A year later, there were 90,000. And by May 2003, there will be 115,000. There will be better availability in extended and regular cabs. DG5 West Coast mirrors are now available on chassis cab models. Also available: SEO 9F7, and the SPF uplevel power extendable camper mirror.

Upfitter integration web site

Beth Montagna, supervisor in the upfitter integration group, said the upfitter integration Web site will be the primary source for body builders updates (

Additional links have been added to improve navigation and efficiency. The format allows printing on standard 8½×11" paper. The web site will archive previous model year publications, beginning with 1999. A courtesy copy of the Body Builders Manual will be made available on CD-ROM once a year, and the 2003 mailing was made in late October.

What's new: a component locator page; upfitter provision subsystem (dedicated connector for PTO); body builder connector (4000-PPM signal added); detailed system operating instructions for Fast Idle (UF3) and PTO options; connector detail and location illustrations; detailed electrical schematics for many subsystems.

Of special interest to upfitters: connectors have been provided to allow easy interface for upfitter equipment rather than splicing into existing harnesses. These subsystems include: upfitter provision (PTO-related functions); trailer wiring (Class 2 and Class 3 vehicles); body builder connector (exterior lighting and signaling, power, and VSS); and a ground block located next to the Body Builder Connector for easy ground termination.

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