GM Unveils Newest Tilt-Style Crew-Cab Along with Sweeping Product Changes

May 1, 2001
GENERAL MOTORS (GM) officials arrived in force to let the National Truck Equipment Association membership know that GM is bringing new truck models and

GENERAL MOTORS (GM) officials arrived in force to let the National Truck Equipment Association membership know that GM is bringing new truck models and options into the commercial lines, based on GM's model of meeting the market's needs.

New at GM dealers this year will be the tilt version crew-cab, said Dan Cutler, GM presenter for the tilt-cab product.

The tilt crew-cab comes in two varieties. The W4500 Crew-Cab is a 14,500-lb GVW product. The W5500 Crew-Cab provides the operator with a 17,950-lb GVW vehicle. Both the W4500 and the W5500 have the same two wheelbase options available, a 150-inch wheelbase and a 176-inch wheelbase.

The W4500 and W5500 crew cabs are available with the 4HE-1TC, 175-hp diesel engine that provides 347 lb-ft of torque at 2000 rpm. This combination is matched with the 450-43LE Aisin automatic transmission.

The cab layout is essentially the same between the two vehicles. Except for the beefier rear axle in the W5500, it would be difficult to differentiate the two vehicles. However, there are two subtle differences between the two.

Braking power gets a real boost in the W5500 from the power-over-hydraulic braking system. This system also gives the W5500 a behind-the-cab brake fluid reservoir. The W4500 carries the vacuum-over-hydraulic system. That stopping power is transferred to the roadway using two different types of tires between the two vehicles.

The W4500 uses a 215/85R-16E (10-ply) tire mounted on a 16-inch rim. The heavier W5500 uses a 225/70R-19.5F (12-ply) tire mounted on a conventional 19.5-inch rim. Obviously the taller rubber and stiffer suspension provides a little higher overall profile to the W5500.

The tilt crew-cab includes some impressive options for this type of vehicle. Front power windows combined with front and rear area power door locks offer a new convenience to the driver. The rear cab air-conditioning and heating option also provides a controlled environment that could make the truck comfortable in harsh environments.

Along with a list of other options, the optional oil pan heater and auxiliary transmission cooler will keep everything on the underside of the cab at the right temperature level.

Electrically, the W4500/5500 crew-cab version is similar to the regular cab versions. The left-hand midship and back-of-frame upfitter connectors are wired as follows: red/yellow for cargo room lamp with cab switch, red for general hot wire, red/green for marker lamps, and black for ground applications.

“Do not modify the wheelbase for the crew cab,” said Cutler. “I just can't stress that enough. GM does not want this frame to be modified.”

WT Series

August 2001 brings the newly accessorized WT5500 to the dealer's showroom. The WT5500 is equipped with the new Allison 1000 automatic transmission. This transmission is a five-speed overdrive with a lock-up converter system, parking pawl, and electronically control shift points.

The 2001 model year also brings new upfitter connections through the truck chassis. The blue and brown bullets have been traded for two, 4-wire Packard connectors. These are located at the left-hand midship and the back-of-frame positions.

A bullet connector will be located at the rear area of the chassis and the rear crossmember. This simple back-up alarm connecter will show a black/blue wire for ground and a red wire for power.

C and T Series

“Don't forget that we have something that can't be found with many truck manufacturers,” Mike Eaves said. “There is a definite market for gas engine, medium-duty trucks, and GM has that.”

Eaves is referring to the Vortec 8100MD gas engine. The engine is available in two horsepower ratings, the 270-hp (base LQY) and the 210-hp (credit option LQQ). The engine also carries an optional Low Emissions Vehicle (LEV) certification, (code VCL), if desired. There is an LPG conversion (code R7G).

The Caterpillar 3126E — LEV engine has two horsepower ratings, a 201-hp (code LQA) and the 216-hp (code LPN). The addition of the LEV status does mandate a catalytic-style converter, but it does provide a 50-state LEV certification.

This year GM will replace the Caterpillar 175-hp (code LSV) with a 190-hp (code LPR). The engine will be equipped with a converter catalyst, but the engines are not LEV-certifiable.

“Because of the reliability and durability improvements that we've made, there are real opportunities to utilize this engine in the marketplace today. This engine can add an entire segment of business to your company,” Eaves said. “Also, Janesville will now be electronically programming all engines at the time of installation.”

GM is coupling the Vortec 8100MD to an optional MT 643G (SEQ code ME4) transmission this April. Another group of transmission options will be introduced for the GM medium-duty C product. These include the Allison 2000 (code MX4) and 2400 (code MTW) series of five-speed, electronically controlled automatic transmissions, along with the Eaton AutoShift (SEO code MR3).

The Allison transmissions have a column mounted gear selector, and the 2400 is equipped with a parking pawl. The GM versions are acceptable to the Caterpillar 3126E, 210-hp engine. The 3126E produces 520 lb-ft of torque.

The Eaton AutoShift model FSO 8406 ASX is a three-pedal system that utilizes a clutch only for starting and stopping. It is available behind the Caterpillar 3126E at 210 hp.

“GM is adding some other changes to the transmission ordering process,” said Eaves. “We are acknowledging the market move towards automatic transmissions that is now taking place in the conventional cab, medium-duty market.”

For the 2002 model year, GM will make automatic transmissions standard for the C-series. The AT-545 will be the base transmission on the C-6 and C-7. The C-7H064 will come standard with the Allison MD-3060.

Other additional changes to the C-series product include:

  • The 34,000-lb Hendrickson RS343 rear tandem suspension replaces the U340 series suspension.

  • A revised Dana DS44 tandem rear axle will be introduced.

  • The Dana-Spicer S150-S, 15,000-lb rear axle replaces the 15040 series axle.

  • An optional 150-amp alternator will replace the 130- and 140-amp optional alternators.

  • Dust shields will be added to the rear four-piston hydraulic brake option (code JNC).

Tee Up

GM has been working on improvements that will reduce the shifting effort currently required of a driver using a T-series with a manual transmission. According to Eaves, this effort has been successful. GM has eliminated the five-speed manual transmission as an available option. Additionally, the T-series will have Eaton Boosted six-speed synchronized transmissions available in the FS-5406 and FS-6406 models.

For all manual transmissions in a T-series product, several newly revised clutch features have been added to the manual transmissions. On the single plate clutch, a new design that helps eliminate drag is offered (code MTD). For the two-plate Eaton Solo clutch, the automatic adjustment has been improved to provide quicker system response (code MPK). And the Eaton single plate Solo clutch model will be added for the T-series.

Viva Toluca

GM's Mexican operation in Toluca, Mexico, continues to be the production point for 3500HDs. This year's model has all of the options that the pre-Toluca models had, with the exception of the paint. “This is a base-coat finish, not a clear coat as the previous models had.”

When this cab and chassis is used in a wrecker application, the GM code 5X9 can be used to order a special ABS brake algorithm that won't place the brakes into anti-skid mode when the brake is applied under load conditions.

“There are some big changes in the vans for the 2002 model year,” said Mike Johnson, the GM van presentation presenter. “We've been focusing on the Savana and Express Cargo. We think we have some pretty sweeping changes.”

GM is bringing some interior changes to the line. Air-conditioning will be a standard item in 2002. Keyless entry is available for the 2002 model year. The vans will now also have a rear heater option. For the Cargo product, the 7,100 GVWR (code C5Y) has been eliminated.

New for the Savana and Express Cutaway is a standardized ambulance package (code YF2) for GMC and Chevrolet. The 11,000- and 11,500-GVWR package has been deleted. Additionally, the 4.56 rear axle ratio (code HC4) has been deleted.

New Style C/K Models

Several cosmetic changes are in store for the new style C/K model in 2002. For vehicles equipped with automatic transmissions, the programmable automatic door locks will now lock when taken out of park and unlock when put in park. Silverado models will have a composite-coated pickup box as standard equipment for the truck. Additionally, the Z82T package will include a 7-way to 4-way trailer lighting package adapter.

This year the snowplow prep package (code VUY) will receive an upgrade.

  • Additional front spring capacity.
  • Increased cooling capacity.
  • 10-amp power for backup and roof mounted emergency lights.
  • 130-amp alternator and heavy-duty electrical connections.
  • Transfer case shields.
  • Forward lamp wiring harness.
  • Mounting location for snowplow controls.
  • 42mm access hole with grommet in front of dash panel.
  • Transmission oil cooler with automatic transmission.
  • High capacity air cleaner.

The ambulance prep package (code YF2) also received a similar upgrade. The prep package is for C/K36403 models.

  • DuraMax 6600 diesel with Allison five-speed automatic transmission.
  • Dual batteries.
  • Dual 100-amp alternators.
  • Center console, CHMSEL, and cargo lamp items deleted.

The C/K 3600 cab and chassis will have PTO availability with the 6.6 liter DuraMax and the 8.1 liter Vortec engines. Two forced RPOs will provide standard content for the GMT800, 3600-model chassis cab trucks. Code M1F and code PTO must be used to get a revised chassis cab floor contour that will allow the PTO to be installed. This will also provide additional heat shielding plates to be installed on the truck. GM does not recommend retrofitting a chassis cab if the vehicle does not have the codes PTO and M1F.

“The printed edition of the upfitters manual has been eliminated,” says Steve Strine, the GM presenter for upfitting activities. “The only exception to that is for new models that require some preliminary information dispersement to commercial body manufacturers.”

According to Strine, the upfitter integration web site will now become the primary source for upfitters information. The format of the site has been changed to allow information to be printed on regular 8.5" × 11" paper. The web site will archive previous years' model information, beginning with the 2000 model year.

GM's web address for upfitters is