1985 International S-Series

From 1977 through 2001, International Harvester (later Navistar International) produced the International S series of trucks. IHC Loadstar and IHC Fleetstar, both of which are medium-duty trucks, were combined into a single product line with the introduction of the S series. It was placed below the Transtar and Paystar Class 8 convention. Here we will talk about the 1985 International S-Series truck.

The IHC S series was manufactured in various configurations for a broad range of applications, including straight trucks, semitractors, vocational vehicles, and severe-service trucks. In addition, the S series was available in a variety of body styles, including a four-door crew cab, a cutaway cab, a cowled chassis, and a stripped chassis (primarily for school buses). There were two, four, and six-wheel drive combinations available, as well as gasoline and diesel engines (the latter only until 1986). The chassis was available with single or tandem rear axles, as well as two, four, and six-wheel drive configurations.

The S series was the final full product line created by International Harvester and was produced in its original form until 1989. The S-Series had a substantial redesign in 1989, and it was divided into many model lines. Product lines based on the “NGV” design were phased in internationally from 2001, with severe-service and bus chassis variants being produced until 2003 and 2004, respectively.

1985 International S-Series Performance and Fuel Economy

The 4000 series, which replaced the S1600 through S1900, was built in various configurations, including single and tandem rear axles and 4×4/6×6 drive choices. Built entirely with diesel engines, the 4000 series included the IDI V8 and DT360/DT466. The 4000 series was manufactured until 2001 when it was superseded with an entirely new

1985 International S-Series Specifications

Engine type: Gasoline 197–236 hp (147–176 kW) Diesel 150–500 hp (110–370 kW)

Vehicle type: heavy truck

Factory Service Manual

The International Truck Manual for the 1985 S-Series is extensive and covers every element of vehicle operation and maintenance. In addition to the vehicle, every S-Series pickup truck comes with a service manual. The following issues are covered in substantial detail in the service manuals:

• Frame
• Front Axle
• Springs
• Brakes
• Steering
• Propeller Shaft
• Exhaust
• Electrical
• Front End Sheet Metal
• Lubrication
• Clutch
• Engine (Diesel) – 6.9L, 9.0L, DT/DTI 466 Engine
• Engine (Gasoline) – V-345, V-392
• Transmission – T-17, T-18 (New Process NP-435)
• Rear Axle
• Fuel Tanks
• Body Cab/Cowl
• Wheels, Rims & Tires

S-Series truck repair manuals are intended for use by technicians and dealerships who maintain and repair the brand’s vehicles regularly. The owner can guarantee that any automobile maintenance or repairs are performed properly and exactly on every occasion by using these service manuals.

4000 series (now the International DuraStar).

Design, Comfort, and Quality

International Harvester revealed the medium-duty S series at a presentation at the New Orleans Superdome in April 1977. The Fleetstar was replaced by heavier-duty 2200, 2500, and 2600 versions (28,000-45,000 lb gross vehicle weight rating). Lighter-GVWR versions (replacing the Loadstar) went on sale in 1978. The whole lineup’s 21 models featured a high degree of component interchangeability; this standardization helped reduce the number of parts needed by 30%.

Following the termination of the IHC pickup-truck line in 1975, the S series was constructed with a model-specific cab, which replaced the pickup-truck cab used on the Loadstar (designed for the 1957 A series). The design was broader and more vertically oriented than its predecessor. All windows in the cab, including the windshield, were constructed with flat glass to save maintenance expenses. All S-series trucks received a tilting fiberglass bonnet, similar to the Loadstar’s tilting hood debuted in 1972.

Owner’s Manual

When it came to a 1985 International S-Series Owners Manual, included was all of the important details about the vehicle’s future operation and maintenance.

• Safety and security
• Operation of each component
• Driving
• Interior Features
• Maintenance and care
• Vehicle specifications

When and how to use the numerous features and functions of their vehicle will be explained in detail in this operator’s manual, written just for vehicle operators.

Late Model Development

The S series was manufactured mostly unchanged throughout the 1980s, and 1987 saw many revisions to the S-series trucks. S-series trucks were rebadged to match the company’s corporate move from International Harvester to Navistar International (alongside all International vehicles). The term “International” at the top of the grille was replaced with a red Navistar “diamond” badge, with “International” in red at the bottom left. The IHC “tractor” badge on the steering wheel was replaced with a Navistar diamond insignia on the inside. In a significant move, International became the first truck manufacturer to develop a medium-duty product line powered only by diesel engines in 1987.