International Harvester 656: Evolution of a Farm Workhorse with Hydrostatic Innovation

Most farms have a utility tractor around. It usually mounts a hydraulic loader but may also be used with other powered implements. The utility will perform a lot of different jobs around the farm and it gets the tractor equivalent of stop-and-go commuter miles. As a farmer upgrades his equipment, yesterday’s main tractor often becomes today’s utility tractor, so “ye olde utility” may have a long life on a farm.

By the early 1960s International desperately needed new tractors to overcome the lead John Deere had gained on them in the late 1950s. Knowing a big chunk of that gain was International’s own fault didn’t help. The debacle of the 560’s final drive failures haunted the company like a persistent poltergeist. Well, International got it right with the 706 and 806, and soon a smaller 606 and a larger 1206 joined the ranks. While these tractors didn’t move them past the “Big Green Machine,” at least they put them within spitting distance.

In 1966, the 606 received a number of upgrades and became the first of the 56 series tractors, the 656. The 756 and 856 followed shortly but that isn’t the big story. The 656 became the point tractor for a big innovation in tractor technology, the hydrostatic drive. IH had been working on a hydrostatic drive since the early 1960s and used one in their innovative HT-340 gas-turbine tractor. IH had big plans and the 656 would be the first production tractor to bring hydrostatic drive to the farm.

Hydrostatic drive, trade named Hydro by IH, didn’t quite make the intro of the 656 line, but had its own debut in the summer of 1967. So what’s hydrostatic drive? You could say it’s an early CVT (Continuously Variable Transmission). You could also say it’s a form of power shift. In reality it’s a hydraulic drive system where the engine drives a huge pump on one side and a huge hydraulic motor is connected to the final drive. In between is a control that varies the volume and pressure going from the pump to the motor. This is a vastly simplified description, of course.

On the upside, the Hydro had infinitely variable speed control which was very useful for many farm tasks where a lot of forwards and back operation is needed. On the downside, there’s some power loss and it was possible to overheat the transmission oil in heavy use. They also weren’t simple to service or repair for owners and techs used to gears.

The Hydro 656 was well received, as were the other Hydros that followed—the 544, 826 and the first 100+ hp hydrostatic tractor, the 1206. Depending on whom you ask, you will hear tales of woe or tales of joy regarding the IH Hydros when some old farmer bends your ear. The truth is somewhere near the middle. A well-maintained Hydro used within its capabilities could last as long as any other tractor. When used beyond the limits, or neglected, they could fail rather spectacularly. Most will agree they had somewhat more no-fault-of-the-operator failures than the average gear-drive tractors but they certainly weren’t a disaster. On the right farm, they were a Godsend and worth a little extra trouble.

There was more to the 656 than the Hydro. They also came with a five-speed mechanical trans with a torque amplifier. You could order them with either a 262-cid gas six (64 PTO hp) or a 282-cid diesel. By the late 1960s, gas tractors were on the way out and most 656s are found with the D282 diesel. It could be ordered with a wide or narrow front axle. Most came with a three-point hitch, PTO and drawbar but a belt pulley drive was still on the options list.

The D282 six-cylinder had debuted with the 560 line in 1958 and was a reworked gasser. It was a four-main, naturally aspirated, dry-sleeved, indirect-injected powerplant with not quite enough head bolts, but by the time the 656 came along, the bugs were worked out and the engine had gained some power along the way. A big-bore, unsleeved 301-cid version (D301) was produced and used in trucks and combines.

The 656 was produced through 1972 and superseded by the upgraded 666 (the Devil’s tractor… muahahahaha!). The 666 was similar in concept but used the D312 diesel, which was a relative of the legendary D360 engine. For 1973, the hydrostatic versions of the 666 were renamed the Hydro 70.

The 656, Hydro or gear drive, was a popular tractor and a bit more that 8,200 were built into 1973. Like John Hoshock’s 1970 Hydro shown here, many are still at work. There isn’t a better testament to quality than that! DW

FREQUENTLY ASKED QUESTIONS

How did the hydraulic system of the Farmall 656 work, and what capacities did it offer?

The hydraulic system of the Farmall 656 was designed for efficiency and versatility, boasting ample capacity for a range of agricultural tasks. Here’s a breakdown of how it functioned and the capacities it offered:

Primary Hydraulic System

• Flow Rate: The main hydraulic system had a total flow rate of 12 gallons per minute (gpm).
• Power Steering: Out of this, 3.5 gpm was specifically allocated to operate the hydrostatic power steering, ensuring smooth and effortless steering control.

Transmission and Remotes

• Lubrication and Power: The remainder of the primary system’s capacity, 8.5 gpm, was used to lubricate the transmission and provide hydraulic power to the remote outlets, enhancing the tractor’s operational flexibility.

Secondary Hydraulic Features

• Hitch System: A separate hydraulic pump provided an additional 7.5 gpm dedicated to the tractor’s hitch. This system could also work in tandem with the primary system, offering enhanced capacity when the hitch was inactive.

Optional Power-Shift PTO

• Additional System: For tractors equipped with the power-shift power takeoff (PTO), an extra 3 gpm system was included. This system specifically powered the hydraulic clutch for the PTO, completing the tractor’s robust hydraulic capabilities.

In summary, the Farmall 656’s hydraulic system was a well-orchestrated blend of multiple systems, each playing a critical role in the machine’s performance and versatility in the field.

What safety features were included in the 656 Hydro’s design?

Safety Features in the 656 Hydro’s Design

The 656 Hydro was equipped with several innovative safety features to enhance operator control and comfort. Here’s a breakdown:

• Neutral Position Design: The speed ratio selector in the 656 Hydro featured a uniquely designed guide slot. This slot included a horizontal step at the neutral position, effectively preventing the operator from accidentally overshooting it when shifting between forward and reverse.
• Inching Pedal for Panic Stops: Despite being clutchless, the tractor included an inching pedal specifically for emergency stops and to boost operator confidence. Activating this pedal released the hydraulic pressure from the transmission pump, bringing the tractor to a swift halt.
• Gradual Clutch Simulation: To prevent abrupt starts, especially when the speed-ratio lever was set to extreme positions, the design incorporated a system that gradually pressurized the pump. This mimicked the smooth engagement of a mechanical clutch, allowing for precise and controlled movements, particularly useful for delicate operations like attaching equipment or performing precision loader work.

These features were not only safety measures but also contributed to the tractor’s ease-of-use, ensuring more controlled operations in varied agricultural tasks.

What was the function of the Torque Amplifier in the Farmall 656?

The Torque Amplifier in the Farmall 656 served a vital role in enhancing the tractor’s versatility and performance. It effectively expanded the transmission options, allowing the operator to access a total of ten gears. This feature provided a high and low range for each gear, enabling seamless shifting on the go. The result was improved adaptability across various farming tasks, from plowing fields to navigating challenging terrains, offering both power and control when needed.

What was unique about the hydrostatic transmission in the 656 Hydro compared to others?

**Hydrostatic drive, trade named Hydro by IH, didn’t quite make the intro of the 656 line, but had its own debut in the summer of 1967. So what’s hydrostatic drive? You could say it’s an early CVT (Continuously Variable Transmission). You could also say it’s a form of power shift. In reality, it’s a hydraulic drive system where the engine drives a huge pump on one side and a huge hydraulic motor is connected to the final drive. In between is a control that varies the volume and pressure going from the pump to the motor. This is a vastly simplified description, of course.

The 656 Hydro’s transmission was a product of over a decade’s worth of innovation, drawing inspiration from heavy-duty torque converters and fluid-drive systems from the automotive world. Engineers experimented with hydraulic pumps connected to individual wheel motors, aiming to perfect a design that balanced performance with reliability.

On the upside, the Hydro had infinitely variable speed control, which was very useful for many farm tasks where a lot of forwards and back operation is needed. It offered a design reminiscent of the hydrostatic transmission found in successful lines, but with a key distinction: both the hydraulic pump and motor featured variable-displacement cylinders. This allowed for greater flexibility and control.

On the downside, there’s some power loss, and it was possible to overheat the transmission oil in heavy use. They also weren’t simple to service or repair for owners and techs used to gears. Despite these challenges, the unique engineering of the 656 Hydro set it apart, making it a notable advancement in the field of agricultural machinery.

What were the principal variants of the Farmall 656, and what features did they have?

The Hydro 656 was well received, as were the other Hydros that followed—the 544, 826 and the first 100+ hp hydrostatic tractor, the 1206. Depending on whom you ask, you will hear tales of woe or tales of joy regarding the IH Hydros when some old farmer bends your ear. The truth is somewhere near the middle. A well-maintained Hydro used within its capabilities could last as long as any other tractor. When used beyond the limits, or neglected, they could fail rather spectacularly. Most will agree they had somewhat more no-fault-of-the-operator failures than the average gear-drive tractors but they certainly weren’t a disaster. On the right farm, they were a Godsend and worth a little extra trouble.

There was more to the 656 than the Hydro. They also came with a five-speed mechanical trans with a torque amplifier. You could order them with either a 262-cid gas six (64 PTO hp) or a 282-cid diesel. By the late 1960s, gas tractors were on the way out and most 656s are found with the D282 diesel. It could be ordered with a wide or narrow front axle. Most came with a three-point hitch, PTO and drawbar but a belt pulley drive was still on the options list.

While the Hydro 656 shone on many farms, the Farmall 656 lineup offered more than just hydrostatic innovation. Among the principal variants were the High-Clear and the Western Special. The High-Clear variant was engineered for exceptional ground clearance, providing 37 inches under the rear axles and 34 inches at the front—an impressive leap from the standard 15 and 21 inches. This feature made it particularly valuable for operations requiring higher clearance.

Meanwhile, the Western Special, a unique Wheat Land variant, was built on the Farmall chassis. This model featured a more enclosed operator’s station and included shockproof lights and a PTO with a power shift hydraulic clutch. It even offered an optional cab for added comfort. Unlike most standards, it maintained adjustable axles and the typical Farmall ground clearance, setting it apart from the rest.

By 1966, the International utility version of the 656 was available in both standard and High-Clear variations, broadening its appeal. Notably, by the end of that year, nearly 16,000 units had been built, marking a significant milestone in the Farmall legacy.

How was power transmitted from the engine to the wheels in the Farmall 656?

“In reality, it’s a hydraulic drive system where the engine drives a huge pump on one side and a huge hydraulic motor is connected to the final drive. In between is a control that varies the volume and pressure going from the pump to the motor.” This innovative hydraulic setup works in tandem with a traditional mechanical system to efficiently transmit power to the rear wheels.

The power from either engine is initially transmitted through a robust 12-inch Dyna-Life single-dry-disc clutch. This component is crucial for managing the engagement between the engine and the drivetrain. The system then feeds into a five-speed sliding-spur-gear agricultural transmission, ensuring smooth and reliable power delivery.

Further enhancing the transmission is the gear reduction at the differential, paired with bull-gear type final drives. These components work together to manage and optimize the power flow to the wheels, providing the necessary torque and handling for various tasks.

For those seeking even greater versatility, an optional Torque Amplifier is available. This feature effectively doubles the number of available gears to ten, allowing for high/low shift on the fly for each gear. It significantly enhances the tractor’s adaptability to different working conditions.

Moreover, tractors without the Torque Amplifier option can be equipped with a forward-reverse attachment. This attachment provides five forward gears and five reverse speeds, which are slightly higher than their forward counterparts. This innovative feature simplifies repetitive forward-reverse operations, making tasks like loader work more efficient and less cumbersome.

By combining advanced hydraulic technology with mechanical precision, this system exemplifies a seamless integration of power and control, tailored to meet the demands of modern agricultural tasks.

What series did the International 656 tractor replace, and when was it introduced?

In 1966, the 606 received a number of upgrades and became the first of the 56 series tractors, the 656. The 56 series was introduced specifically to replace the older 06 series, marking a significant evolution in tractor design and functionality. The transition began with the launch of the 656 model in 1965, setting a new standard in agricultural machinery with its innovative features and improved performance.

This introduction not only signaled the end of the 06 series but also ushered in a new era for farmers seeking enhanced efficiency and reliability. By refining and updating the existing 606 model, the 656 embodied the technological advancements that characterized the 56 series, offering greater power and versatility for a variety of farming needs.

Why was the 656 chosen as the platform to introduce a hydrostatic transmission?

The decision to use the 656 as the platform for launching a hydrostatic transmission was largely strategic. The 656 replaced its predecessor, the 606, with minimal changes but included a crucial upgrade: the addition of new utility and row-crop versions equipped with an innovative hydrostatic transmission designed by the company.

This choice was influenced by the tractor’s popularity. As it was one of the most widely used models, introducing cutting-edge technology on a familiar platform ensured a smooth transition and higher acceptance among users. The decision was highlighted in a Machine Design magazine article from June 8, 1967, emphasizing that the tractor’s extensive user base and reliability made it the ideal candidate to debut this technology.

By leveraging the existing trust and familiarity farmers had with the 656, the brand aimed to encourage adoption of the new transmission system, reducing risks and uncertainty for both the company and its customers.

What were the engine specifications for the 656 Hydro?

Engine Specifications for the 656 Hydro

The 656 Hydro tractor offered two engine options. Buyers could choose between a C-263 cubic inch gasoline engine or a D-282 cubic inch diesel engine. These engines were designed to run at higher speeds, with a governing rate of 2,300 rpm, as opposed to the 1,800 rpm commonly found in other models. This increased rpm allowed the engines to deliver approximately 66 horsepower at the power takeoff and 52 horsepower at the drawbar in both the gasoline and diesel versions.

Transmission and Speed Capabilities

Power from the engine was efficiently delivered to the ground through a hydrostatic transmission. This was paired with a two-speed Hi Lo gearbox, leading to a conventional differential and bull-gear final drive. The hydrostatic transmission allowed for variable speed settings:

• High Range:
  • Forward speeds of 0–20 mph
  • Reverse speeds of 0–9 mph
• Low Range:
  • Forward speeds of 0–8 mph
  • Reverse speeds of 0–4 mph

How did the hydrostatic transmission of the 656 differ from the Sundstrand Corporation’s design?

The hydrostatic transmission of the 656 set itself apart through an innovative design that involved years of rigorous experimentation. While it drew inspiration from the automotive industry’s use of torque converters and fluid-drive systems, its final form had unique elements.

A critical difference lay in the transmission’s components: both the hydraulic pump and motor were equipped with variable-displacement cylinders. This diverged from the design by Sundstrand Corporation, which was known for its fixed-displacement approach in their widely adopted hydrostatic transmissions.

This variability enabled the 656 to offer more precise control and adaptability, marking a significant evolution in transmission technology.

What was the hydraulic capacity of the Farmall 656, and what systems did it power?

The Farmall 656 boasted impressive hydraulic capabilities, featuring a main hydraulic system with a capacity of 12 gallons per minute (gpm). Of this, 3.5 gpm was dedicated to its fully hydrostatic power-steering system, ensuring smooth maneuverability. The remaining 8.5 gpm served dual purposes: lubricating the transmission and powering the remotes.

Additionally, a distinct 7.5-gpm pump powered the tractor’s hitch. This system could also supplement the primary hydraulic functions when the hitch wasn’t engaged. For models equipped with an optional power-shift power takeoff (PTO), a separate 3-gpm system was tasked with operating the PTO’s hydraulic clutch. Together, these features made the 656 an adaptable and versatile farming machine.

What optional feature doubled the number of available gears in the Farmall 656?

The Farmall 656 offered an optional feature known as the Torque Amplifier. This feature effectively expanded the number of gears from five to ten by allowing high/low shifting in each gear while the tractor was in motion.

What safety feature was incorporated into the 656 Hydro’s clutchless design?

The 656 Hydro integrated a crucial safety feature to prevent sudden, unintended movements when operating the machine without a traditional clutch. Engineers crafted a system that gradually applied pressure to the hydraulic pump as the operator released the clutch pedal. This mechanism mimicked the smooth engagement of a traditional clutch through its friction point. Originally designed as a safety measure, this feature not only enhanced control but also offered convenience for tasks requiring precision, such as slowly moving attachments into place or conducting precise loader operations.

What were the principal variants of the Farmall 656 during its first year of production?

The initial production year of the Farmall 656 introduced two main variants: the High-Clear and the Western Special.

• High-Clear Variant: This model offered significantly increased ground clearance with 37 inches under the rear axle and 34 inches under the front, compared to the standard 15 and 21 inches. This higher clearance made it particularly suitable for specific agricultural tasks requiring more vertical space.
• Western Special Variant: This wasn’t a standard version but was tailored for wheat farming, based on the Farmall chassis. It featured a more enclosed operator’s station for added comfort, shockproof lighting, a PTO with a power shift hydraulic clutch, and the option of an enclosed cab. Notably, it maintained adjustable axles and the Farmall’s typical ground clearance.

By 1966, an International utility version of the 656 was also available in both standard and High-Clear variations. By year’s end, nearly 16,000 units were produced, marking a successful launch for these versatile machines.

What changes were made to the Farmall 656 in 1967?

In 1967, the Farmall 656 underwent several notable updates. Most visibly, the tractor received a refreshed appearance, including a redesigned grille. The older white mesh grille was replaced with a modern tubular steel version. Additionally, both the utility and row-crop models now sported the label “International” on their side panels. However, on the row-crop version, “Farmall” appeared beneath the number on the badge located on the grille housing.

A significant technical advancement for the Farmall 656 was the introduction of an innovative hydrostatic transmission. This new transmission was featured in both utility and row-crop models. The decision to introduce this advanced technology on the 656 stemmed from its popularity within the company’s lineup.

The hydrostatic transmission was a culmination of extensive research and development, drawing from over a decade of experimentation. The company had explored various technologies, such as torque converters and fluid-drive transmissions borrowed from the automotive sector, as well as hydraulic pumps linked to individual wheel motors. The final design closely resembled a successful model by Sundstrand Corporation, though with distinct enhancements including variable-displacement cylinders in both the pump and motor aspects of the 656’s transmission system.

How was power transmitted from the engine to the rear wheels in the Farmall 656?

Hydrostatic drive, trade named Hydro by IH, didn’t quite make the intro of the 656 line, but had its own debut in the summer of 1967. So what’s hydrostatic drive? You could say it’s an early CVT (Continuously Variable Transmission). You could also say it’s a form of power shift. In reality it’s a hydraulic drive system where the engine drives a huge pump on one side and a huge hydraulic motor is connected to the final drive. In between is a control that varies the volume and pressure going from the pump to the motor. This is a vastly simplified description, of course.

To truly understand the power transmission in the Farmall 656, let’s dive into the original setup. Power from the engine was channeled to the rear wheels through a robust 12-inch Dyna-Life single-dry-disc clutch. This clutch connected to a five-speed sliding-spur-gear agricultural transmission, ensuring reliable power transfer.

The system also included gear reduction at the differential and bull-gear type final drives, providing the necessary torque and control for various tasks. For those seeking enhanced performance, an optional Torque Amplifier was available. This ingenious addition doubled the number of gears to ten, offering a high/low shift on the fly for each gear.

For operators focused on efficiency, tractors without the Torque Amplifier option could be equipped with a forward-reverse attachment. This feature provided five forward gears alongside five reverse speeds, slightly higher than their forward counterparts. Such versatility made loader work and other repetitive operations smooth and efficient.

This combination of traditional and innovative transmission solutions illustrates the versatility and adaptability of the Farmall 656, catering to varied agricultural needs.

What engine specifications are included in the International Harvester 656 Tractor Engine Parts Manual (Engine)?

Engine Specifications in the International Harvester 656 Tractor Engine Parts Manual

The International Harvester 656 Tractor Engine Parts Manual encompasses comprehensive details on several key engine specifications. Here’s a breakdown of the essential features covered:

• Engine Type: The manual provides specifications for the diesel engine model, particularly focusing on the hydro engine.
• Application: It includes details specific to the 100 Hydro Tractor Engine, underscoring configurations related to hydro engine applications only.
• Component Details: Expect in-depth coverage of parts, assemblies, and subsystems involved in the overall functioning of the tractor’s diesel engine.
• Operational Guidelines: Insights into how the different components work together and guidelines for optimal maintenance and performance.

This manual is an invaluable resource for anyone looking to understand or service the engine of an International Harvester 656 tractor.

What types of transmissions are covered in the Farmall 656 Tractor Parts Manual (Chassis)?

The Farmall 656 Tractor Parts Manual (Chassis) includes detailed information on both gear and hydrostatic transmissions for the 656 model tractors, which are available in both gas and diesel versions. This manual provides comprehensive guidance on parts specific to each transmission type, ensuring you have the right tools to maintain or repair either configuration. Whether you’re dealing with a gear-driven or hydrostatic system, this manual covers all the necessary components and assembly details.

What tractors are compatible with the Farmall 656 Tractor Hydrostatic Transmission Service Manual?

The Farmall 656 Tractor Hydrostatic Transmission Service Manual is specifically designed for use with tractors that feature a hydrostatic drive. This includes both gasoline and diesel models of the 544 Tractor, specifically those configured as row crop variants with a hydrostatic transmission.

What items are included in the International Harvester 656 Tractor Parts Manual?

What’s Inside the 656 Tractor Parts Manual?

Discover a comprehensive guide with the 656 Tractor Parts Manual, detailing essential components and attachments designed to enhance the utility and versatility of your tractor. This manual includes detailed information on:

• Ditcher– Perfect for creating drainage channels or trenches.
• Tool Bar Attachments (Various Sizes)– Versatile attachments such as the 10 and 12 Tool Bar options for various field applications.
• Box Scraper 100– Ideal for leveling and grading surfaces.
• Pulverizer 11– Efficient in breaking up soil for more refined landscaping or agricultural tasks.

Priced at just $19.99, this manual offers a valuable resource for optimizing your tractor’s performance. Don’t miss out on the opportunity to make an informed choice!

What does the International Harvester 656 Tractor Operators Manual fit?

The International Harvester 656 Tractor Operators Manual is specifically designed to be compatible with the International Harvester 656 Tractor models. These include the gas, liquid propane (LP), and diesel variants. It is suitable for both row crop and utility configurations. Additionally, the manual covers tractors with either hydrostatic or gear drive systems.