Production 1977-2001 | Layout 4x2
6x4 | |
 | ||
Manufacturer International Harvester (1978-1986)
Navistar International (1986-2001) Also called Navistar International 4000-Series
Navistar International 8000-Series Class Class 6-7 medium-duty truck Body style Truck (conventional)
Tractor
Straight truck
Bus
Cowled chassis (conventional)
Stripped chassis (forward control) | ||
The International Harvester S-Series is a range of trucks that was manufactured by International Harvester (later Navistar International) from 1977 to 2001. Introduced to consolidate the medium-duty IHC Loadstar and heavy-duty IHC Fleetstar into a single product range, the S-Series was slotted below the Transtar and Paystar Class 8 conventionals.
Contents
The IHC S-Series was produced in a number of variants for a wide variety of applications, including straight trucks, semitractors, vocational trucks, and severe-service trucks. Additionally, the S-Series was produced in other body configurations, including a four-door crew cab, cutaway cab, cowled chassis, and a stripped chassis (primarily for school buses). The chassis was produced with both gasoline and diesel powertrains (the latter exclusively after 1986), single or tandem rear axles, and two, four, or, six-wheel drive layouts.
The last complete product line designed within the existence of International Harvester, the S-Series was produced in its original form through 1989. To reflect the change to Navistar, a major facelift updated the exterior and interior of many models, which were produced through 2001. As a replacement for the S-Series, Navistar introduced the 4000-Series and 7000-Series (known as the International DuraStar and International WorkStar since 2008).
S-Series (1956-1957)
As a nameplate, International Harvester first introduced the S-Series for 1956. Available as the IHC light-duty and medium-duty range, the predecessor R-Series remained in production. In addition, the S-Series formed the basis for its own generation of the IHC Travelall wagon, marking the introduction of a four-wheel drive option for the model.
The heaviest version (the S1840) was produced with a GVWR of 24,000 lb (10,886 kg), powered by a 308 ci "Black Diamond" gasoline engine.
Production of the light duty S-Series ended in 1957, when it was replaced by the A-series. The S-184 heavy version was produced by the Brazilian subsidiary of International Harvester, until its 1966 purchase by Chrysler.
First generation (1978-1989)
In April 1977, International Harvester unveiled the medium-duty S-Series at an event at the New Orleans Superdome. Initial sales were of heavier-duty 2200, 2500, and 2600 models (28,000-45,000 lb GVW), replacing the Fleetstar. In the summer of 1978, lighter-GVWR models (replacing the Loadstar) were released for sale.
Following the discontinuation of the IHC pickup-truck line in 1975, the S-Series was designed with a model-specific cab, replacing the pickup-truck cab used for the Loadstar (designed for the 1957 A-Series). More vertically-oriented than its predecessor, the design was much wider as well. To lower maintenance costs, all windows in the cab were designed with flat glass, including the windshield. Similar in style to the tilting hood introduced for the Loadstar in 1972, all S-Series trucks were given a tilting fiberglass hood.
The S-Series would be produced throughout the 1980s largely unmodified. 1987 would mark several changes to the S-Series trucks. To reflect the corporate change of the company from International Harvester to Navistar International, S-Series trucks saw changes in their badging (alongside all International vehicles). On the grille, the word "International" across the top of the grille was replaced by a red Navistar "diamond" logo alongside "International" in red at the bottom left of the grille. Inside, the IHC "tractor" logo on the steering wheel was replaced by a Navistar diamond logo. In a major shift, for 1987, International became the first truck manufacturer to produce a medium-duty product line powered exclusively by diesel engines.
Models
Originally intended to use the International Tristar nameplate, the S-Series consolidated the aging Loadstar and Fleetstar trucks under a single product line. Tandem-axle (6x4) versions of the S-Series were named F-series trucks.
1978-1983 models
Second generation (1989-2001)
During 1989 production, the International S-Series underwent a major redesign. In the interest of the aerodynamics, the truck was given a lower hoodline with smoother contours to the hood and fenders. In the interest of functionality, the interior controls were completely redesigned, with a new dashboard; a two-spoke steering wheel replaced the previous three-spoke design.
Although the exterior design was well-received, the interior saw several updates (replacing the instrument panel in 1992 and redesigning the rest of the interior in 1995). The second-generation models would remain in production until the end of the 2001 model year.
Models
For 1989, the S-Series naming scheme was updated, partially to reflect the redesign and in favor of the change from International Harvester to Navistar International. Bus chassis were changed from the traditional IHC xxx3 suffix to 3000-Series. Class 5-7 trucks (the previous S1600-1800) were rechristened the 4000-Series. Class 7-8 trucks (the previous S/F 1900 and above) were re-christened the 8000-series. The 8100 was a short-hood tractor, while the 8200 and 8300 were long-hood tractors designed similar to the aerodynamic 9400 Class 8 tractor.
Dropping their S-Series prefix, the popular 2500 and 2600 trucks continued in production as severe service vehicles, slotted below the Paystar in size.
2002 Models
Bus use
Throughout its production, the S-Series would be used as a cowled chassis for bus manufacturers. While used primarily for yellow school buses in the United States and Canada, the S-Series also was used outside of North America as a basis to produce other types of bus bodies. Introduced in 1979, the bus variant of the S-Series would be one of the final models designed by International Harvester before its transition to Navistar. In 1989, the S-Series bus chassis was rechristened the 3000-Series with the fitment of the new-generation Navistar cowl.
Produced until 2004, the bus chassis would outlive its truck counterpart by three years; its 25-year production run is the longest of any product ever sold by International Harvester or Navistar.