AGCO ST55 Tractor 55 hp Overview, Specifications, and Key Features
AGCO ST55 Tractor 55 hp
The AGCO ST55 is a compact utility tractor that offers a reliable 55 horsepower engine. It comes from a well-known partnership between AGCO and Iseki, reflecting a balance of Japanese engineering and international distribution.
Production & Identification
This tractor is part of the ST Series, designed for versatility and medium-duty work. The ST55 stands out for its power in a compact frame, measuring about 137 inches long and weighing 4,417 pounds.
You can use the ST55 for mowing, tilling, loader work, and light construction. Its four-wheel-drive (4WD) chassis gives you improved traction and stability, especially on rough ground.
The hydrostatic power steering and mechanical features make it simple to operate, whether you’re experienced or new to using compact tractors. You can identify the ST55 by its distinct AGCO branding and model decals placed on the engine cover and side panels.
The styling includes a streamlined hood and clear front lights. For further identification, check the product plate that lists the model and serial number.
Manufacturer / Brand
The ST55 was manufactured for AGCO by Iseki, a trusted Japanese tractor maker known for compact and utility tractors. AGCO is based in the United States, but often works with brands like Massey Ferguson, Challenger, and Iseki to deliver high-quality machines worldwide.
Iseki brings decades of experience in building durable tractors for farming and gardening. This partnership helped AGCO expand its lineup of compact models, bringing proven Japanese engineering to North American and international markets.
The branding on the ST55 showcases AGCO’s orange and gray color scheme, but the underpinnings share much with Iseki’s own models. This helps with parts availability and long-term maintenance, since many components are standardized or interchangeable.
Model Number / Series
The “ST55” model number means it belongs to AGCO’s ST Series, and its engine produces about 55 gross horsepower. The ST Series includes other compact utility tractors with different power levels to fit many types of jobs and property sizes.
Within the series, the ST55 was considered the top-end model by horsepower at the time. The model’s features—such as its robust frame, 4WD, and hydrostatic steering—set it apart from basic entry-level compact tractors.
This series targeted small farms, landscaping businesses, equestrian properties, and large-acreage homeowners needing professional-level features. You’ll often see owners comparing the ST55 to similar compact utility tractors from Massey Ferguson or Iseki’s own lines, since they share many mechanical parts.
Factory of Manufacture
Production of the ST55 took place in the Matsuyama factory in Japan. Iseki is known for this manufacturing plant, which has produced compact tractors for decades.
The factory specializes in precise assembly and quality control, following Japanese manufacturing standards. All imported ST55 tractors from this era should show “Made in Japan” markings on their data plates.
This factory also supplied similar units for other brands, which is why you might spot similar models carrying the Iseki or Massey Ferguson nameplate. The partnership with AGCO allowed for broader distribution into North America and other regions.
Years Produced
The AGCO ST55 was produced mainly in the early 2000s. Its main production window was from 2004 until around 2008.
During these years, the ST55 was one option in a full series of AGCO-branded compact utility tractors. If you see an ST55 on the used market, it almost always falls in that year range.
The tractor’s design reflects the technologies and requirements of that era—such as Tier 2 emissions standards, and the growing demand for compact tractors capable of working in a variety of settings. AGCO periodically updated the ST Series lineup, but the ST55’s core mechanical design remained consistent throughout production.
Original List Price (Launch Year)
The original list price for a new AGCO ST55 varied based on optional equipment, region, and the dealer. Around its launch year—2004—the base price was typically in the range of $22,000 to $27,000 USD for a standard configuration.
This price excluded additional features such as loaders, cabs, or specialty tires. For a fully loaded model with front loaders and more attachments, the price could approach $30,000 or higher.
Serial-Number Location
You can find the serial number of the AGCO ST55 on a data plate attached to the side of the tractor’s frame. Most commonly, this plate is located near the front right side (operator’s view) under the engine hood or along the lower right frame rail.
The serial number provides key information for parts ordering and service work. It helps you verify the year of manufacture and configuration.
If you are buying a used ST55, locating and checking the serial number can confirm the tractor’s identity, build year, and if it matches the advertised details. AGCO and Iseki dealers can use the serial number to find data about configuration and production batch.
Table: AGCO ST55 55 hp Compact Utility Tractor Reference
| Topic | Details |
|---|---|
| Production & Identification | Part of AGCO’s ST Series; 55 hp; 4WD; 137″ long, 72.7″ wide, 98.8″ tall; 4,417 lbs; decals on hood and side panels; hydrostatic steering. |
| Manufacturer / Brand | AGCO (Allis-Gleaner Corp.); produced by Iseki in Japan. Shared design influences with Iseki and Massey Ferguson. Brand: AGCO. |
| Model Number / Series | Model: ST55; Series: ST Series; highest horsepower in line; compact utility tractor; used for farms, landscaping, large acreage properties. |
| Factory of Manufacture | Built by Iseki in Matsuyama, Japan; high-quality manufacturing; “Made in Japan” plate; reliable assembly and quality control. |
| Years Produced | Mainly 2004–2008; most models on market from this period; stable features across production years; reflects early 2000s compact tractor design. |
| Original List Price | Base price (2004): $22,000–$27,000 USD; could exceed $30,000 with attachments; positioned as premium compact tractor in AGCO range. |
| Serial-Number Location | Found on a metal plate on right side frame or under engine; critical for parts and service; used for identification and year verification. |
Engine Specifications
The AGCO ST55 uses a reliable diesel engine that balances power, efficiency, and durability. Key features include a four-cylinder design, a 2.8-liter displacement, and a cooling system designed for steady performance in a range of conditions.
| Specification | Details |
|---|---|
| Engine Make & Model | Iseki 2.8L 4-cylinder diesel |
| Fuel Type | Diesel |
| Emissions Tier | Not Rated / Unspecified |
| Cylinders | 4 |
| Displacement | 2.8 liters / 173 cubic inches |
| Rated Horsepower (Gross) | 55.6 hp / 41.5 kW |
| Rated Horsepower (Net – est.) | ~44.2 hp (varies with PTO/Net rating) |
| Peak Torque | Not specified in sources |
| Compression Ratio | Not specified in sources |
| Cooling System | Liquid-cooled |
| Cooling System Capacity | Not specified |
Engine Make & Model
You get an Iseki engine with the AGCO ST55. This is a 2.8-liter, 4-cylinder, diesel engine that comes from a reputable Japanese manufacturer known for producing compact tractor engines.
The design focuses on consistent power, smooth operation, and long-term reliability. This Iseki engine uses indirect fuel injection, which helps improve starting and cold-weather performance.
It’s designed to be low-maintenance and dependable for daily farm tasks.
Fuel Type & Emissions Tier
The engine runs on standard diesel fuel, making it easy to refuel and maintain. Diesel engines like this one are popular in utility tractors due to their efficiency and ability to deliver high torque at lower RPMs.
No specific emissions tier is listed for this model. Given its production era, it does not use advanced emissions after-treatment like DEF (Diesel Exhaust Fluid) or particulate filters.
This can simplify maintenance but might not meet the latest emissions standards required in some regions. Diesel fuel also means the ST55 is suited for both light and heavy tasks.
Cylinders / Displacement
The AGCO ST55’s Iseki engine is a 4-cylinder, liquid-cooled diesel. Four cylinders offer smoother operation and more consistent power than smaller 2- or 3-cylinder designs.
This setup is well-balanced for medium-duty work. Displacement is 2.8 liters, or 173 cubic inches.
Larger displacement helps the engine produce more torque and maintain power under load. This ensures you have enough power for field work, loader operation, and pulling implements.
Rated Horsepower (Gross & Net)
The AGCO ST55 is rated for a gross horsepower output of 55.6 hp (41.5 kW) at 2500 rpm. This is at the higher end for compact utility tractors in this class and gives you significant power for pulling, lifting, or PTO-driven implements.
The net or PTO horsepower is estimated to be around 44.2 hp. The exact figure depends on losses from the drivetrain and accessories but is typically lower than gross horsepower.
This measurement matters if you plan to use powered equipment like mowers, balers, or tillers. The horsepower rating makes the ST55 versatile, capable of tasks ranging from mowing and loader work to heavier field operations.
Peak Torque (Nm @ rpm)
Specific peak torque numbers for the AGCO ST55’s engine are not listed in the provided information or manufacturer specs. However, for a 2.8L four-cylinder diesel of this class, you can expect torque delivery to be strong at low to mid-range RPMs.
Most similar engines offer peak torque somewhere around 150-200 Nm in the 1200-1600 rpm range. This means the tractor can handle heavy loads without needing high engine speeds.
Torque is especially important for fieldwork and ground-engaging implements, where you need the engine to maintain stable RPMs as the load increases.
Compression Ratio
No exact compression ratio is provided in the listed sources. In general, diesel engines in this size and power class typically use a compression ratio between 17:1 and 21:1.
Higher compression ratios are necessary for diesel ignition, helping ensure efficient fuel burn and good cold-start capability. A solid compression ratio helps contribute to better fuel economy, longer engine life, and reliable all-weather starting.
Cooling System & Capacity
The AGCO ST55 uses a liquid-cooled system, which is standard on compact utility tractors. Liquid cooling helps regulate engine temperature during hard work, reducing the risk of overheating and promoting longer life.
Coolant circulates through the engine block and a radiator, pulling excess heat away. This method works better than air cooling, especially during heavy-duty farm or landscaping work.
A specific coolant capacity is not listed in the sources, but tractors in this class often hold around 7-10 quarts (6.6-9.5 liters) of coolant. Always check your owner’s manual for the exact coolant type and capacity needed for routine maintenance.
Power Take-Off (PTO)
The AGCO ST55 tractor offers a versatile PTO system that supports modern implements. The PTO is designed to deliver reliable performance with different types and speeds, fitting a range of farming needs.
| Feature | Details |
|---|---|
| Claimed PTO Horsepower | Approx. 46 hp |
| PTO Type | Independent, Electro-hydraulic Clutch |
| PTO Speeds | 540 rpm |
| Rear PTO RPM | 540 |
| PTO Engagement | Electro-hydraulic |
| PTO Shaft Size (Rear) | 1.375 in. |
Claimed PTO Horsepower
You get a claimed PTO horsepower of about 46 hp with the AGCO ST55. This figure means your tractor can power many implements, such as mowers, tillers, and balers.
PTO horsepower is the usable power delivered from the engine, after accounting for the losses in the drivetrain. This amount of PTO power is suitable for most medium-duty tasks and basic farming jobs on small to medium-sized farms.
It’s important for users to match PTO horsepower with implement requirements, so you don’t overload the tractor or the machine. Keep in mind that actual PTO output may vary based on engine condition and maintenance.
Always check specific requirements for your equipment before use.
PTO Type (Independent / Live / Economy)
The AGCO ST55 uses an independent PTO system controlled by an electro-hydraulic clutch. With an independent PTO, you can engage or disengage the PTO separately from the tractor’s transmission.
This gives you flexibility to operate implements without stopping or shifting gears. The electro-hydraulic clutch allows for smooth engagement and quick response.
When you press the switch, the PTO activates instantly and safely. This design helps prevent wear and tear on implements and tractor components.
Independent PTO systems are considered superior for most users, because they reduce the delay and risk found in live or transmission-driven systems. You can operate mowers, balers, or sprayers with less interruption and more consistent results.
PTO Speeds (540 / 1 000 rpm)
The rear PTO on the AGCO ST55 runs at 540 rpm, which is the standard speed for most North American implements. This matches the needs of common equipment, such as rotary cutters, post-hole diggers, and finish mowers.
The 540 rpm speed is delivered through a 1.375-inch shaft, making it compatible with most attachments. If you use implements designed for this speed, setup is straightforward.
The control system makes engaging and disengaging the PTO simple and reliable. There is no 1000 rpm speed option, so it may not be suitable if you have implements that require higher speed.
For the majority of farm work, 540 rpm covers most use cases and offers solid performance with less complication.
Transmission & Drivetrain
The AGCO ST55 offers a reliable transmission with a focus on versatility for a wide range of tasks. Its drivetrain components are designed for stability, durability, and smooth operation in demanding work environments.
| Feature | Details |
|---|---|
| Transmission Type | 12-speed synchro shuttle manual |
| Number of Gears/Ranges | 12 forward, 12 reverse |
| Top Transport Speed | Approximately 18 mph (29 km/h) |
| Drive Configuration | 2WD or optional 4WD |
| Differential Lock | Standard mechanical |
| Final Drives | Heavy-duty planetary |
Transmission Type (Syncro, Powershift, CVT, HST)
You get a 12-speed synchro shuttle manual transmission with the AGCO ST55. This transmission lets you change directions quickly with a forward/reverse shuttle lever.
A synchro shuttle is different from a basic manual because you don’t have to stop completely to switch between forward and reverse. This is useful for loader work or tasks that require direction changes.
You won’t find powershift, CVT, or hydrostatic (HST) options on this model. The synchro shuttle is simple and reliable.
Number of Gears / Ranges
You have 12 forward and 12 reverse gears with the ST55’s transmission. The setup includes several ranges, each with multiple gears to match speed with task and terrain.
Lower gears provide better pulling strength for tough jobs like plowing or heavy towing. Higher gears are tailored for lighter work or road travel.
This range of gears allows you to dial in the right speed and torque for both fieldwork and transport. The even spread of gears helps with fuel efficiency and operator comfort.
Top Transport Speed
The maximum transport speed on the AGCO ST55 is about 18 mph (29 km/h). This speed makes it efficient to move between fields, barns, or job sites.
You won’t reach highway speeds, but this top speed is typical and safe for utility tractors in its class. It supports moving equipment or products from one place to another without slowing down your operation too much.
You also benefit from smooth shifting between gears at all speeds. The tractor remains steady and manageable on rural roads or farm lanes.
Drive (2WD / 4WD / AWD)
You can choose between a 2-wheel drive (2WD) or a 4-wheel drive (4WD) version of the ST55. The standard setup is 2WD, which suits flat, dry fields and light workloads.
The optional 4WD system offers better traction on loose soil, mud, or slopes. It helps prevent wheel slip and keeps power going to the ground when conditions get tough.
You won’t find all-wheel-drive (AWD) on the ST55. For most agricultural, loader, and utility work, the 2WD and 4WD options give you the flexibility you need.
Differential-Lock & Final Drives
A mechanical differential lock comes standard. When you press the differential lock pedal, both rear wheels turn together, helping you keep going if one wheel is in mud or on loose ground.
The final drives are heavy-duty and designed for long service life under stress. These components transfer engine power from the transmission to the wheels with minimal loss.
Having strong final drives and a robust differential lock gives you peace of mind during tough tasks like plowing or hauling heavy loads. You’ll be glad for this extra traction and durability if you need to work in challenging field conditions.
Steering & Brakes
The AGCO ST55 tractor is designed with a focus on control, stability, and user comfort. Its steering and braking systems are engineered to enhance maneuverability and safety in different working conditions.
| Feature | Description | Type/Specification |
|---|---|---|
| Steering System | Hydrostatic Power Steering | Power-Assisted |
| Turning Radius (With Brakes) | Tight turning for improved maneuverability | Not specified |
| Service Brakes | Wet Disc Brakes | Oil-immersed, durable |
| Parking Brake Type | Integrated with main braking system | Lever-type, mechanical |
Steering System (Hydrostatic / Power-Assisted / Mechanical)
You get a hydrostatic power steering system with the AGCO ST55 tractor. This means turning the steering wheel takes very little physical effort, even when carrying heavy loads or using front attachments.
Hydrostatic power steering uses hydraulic pressure to assist your input, making it easier to handle the tractor during long workdays or in tight spaces. Power steering also helps reduce operator fatigue.
You can steer smoothly at both low and high speeds. The steering is precise and predictable, which leads to more accurate control and less wear on your arms and shoulders.
The hydrostatic system is sealed and protected from dust and water, making it reliable in harsh working environments. Maintenance is simple, and breakdowns are rare due to the robust design.
Turning Radius (With Brakes)
The AGCO ST55 tractor is built for tight turns, which is important when working in small fields, around obstacles, or inside barns. A tight turning radius lets you navigate efficiently and complete tasks faster.
When you use the brakes on one side (brake-assisted turning), the inside rear wheel can slow down or stop, pivoting the tractor more sharply around that wheel. This helps you make very tight turns without needing to reverse or do extra maneuvers.
The actual turning radius with brakes is not specified. Operators report good agility in most working conditions.
This feature is most useful in row-crop farming or tasks that require frequent turning. You can also work closer to fences, edges, or structures, which helps you use your time and space better.
Service Brakes (Wet Disc, Dry Drum, etc.)
The AGCO ST55 uses wet disc brakes, which are also called oil-immersed brakes. These are more durable than dry drum or dry disc brakes.
The braking surfaces of wet disc brakes are submerged in oil, which keeps them cool and reduces wear even during frequent use. Wet disc brakes provide strong, reliable stopping power, even in muddy, wet, or dusty conditions.
Oil immersion prevents the buildup of heat and minimizes the risk of fading, so you get consistent braking every time you press the pedal. This is especially useful for hauling loads, working on hills, or stopping suddenly in emergencies.
Maintenance is reduced because the brake pads last longer compared to dry brakes. Replacement intervals are less frequent, meaning less downtime and lower maintenance costs for you.
Parking Brake Type
The parking brake on the AGCO ST55 is a mechanical, lever-operated system. It’s integrated with the main braking system so you can engage it easily from the operator’s seat without needing to leave the controls.
You lock the brake using a dedicated lever, usually located next to the seat or on the floor. This keeps the tractor securely in place when parked, even on slopes or uneven ground.
Mechanical linkage ensures reliable holding force, and the design is simple for long-term dependability. The lever-type parking brake is easy to check and adjust.
If maintenance is needed, parts are straightforward to access and service. You can keep your tractor safe during stops or storage.
| Subtopic | System Type / Feature | Benefit |
|---|---|---|
| Steering | Hydrostatic Power Steering | Easy, low-effort control; precision |
| Turning Radius | Brake-assisted | Sharp, efficient maneuvering |
| Service Brakes | Wet Disc | Consistent, strong brakes; low maintenance |
| Parking Brake | Mechanical Lever | Secure parking; simple operation |
Cab & Operator Station
You will find the AGCO ST55’s operator environment designed for practicality and efficiency. Comfort, safety, and ease of use are priorities, whether you choose an open station or cab.
ROPS / Cab Option
The AGCO ST55 comes standard with a Rollover Protective Structure (ROPS), ensuring safety if the tractor tips over. This ROPS is built with sturdy materials and meets industry safety standards.
An optional cab enclosure can be installed for extra protection and comfort. Cabs from reputable manufacturers, like Sims Cab Depot, fit the ST55.
These cabs include curved corner posts, external and internal door locks, and durable ABS roofs. The cab doors are removable, and both the front and rear windows are hinged for ventilation and quick access.
The sealed cab design helps protect you from dust, debris, and weather.
Climate Control (A/C, Heater, Filter)
When equipped with a full cab, the AGCO ST55 can include air conditioning and a heater to let you work comfortably in hot or cold conditions. The cab also comes pre-wired for these optional climate control accessories.
You can operate the A/C and heater systems using straightforward controls inside the cab. A basic air filter system is included to reduce the amount of dust and pollen inside the operator area.
This improves air quality and lets you focus on your work, even during longer shifts or when mowing dusty fields.
Seat & Suspension
The standard operator’s seat on the ST55 has a contoured design with a durable covering to resist wear. Height and distance adjustments are available to fit your body comfortably.
The seat has moderate cushioning and integrated armrests for good operator ergonomics. A mechanical suspension system, built into the seat mount, helps absorb shocks from rough terrain.
An upgraded seat with extra padding or an improved suspension may be available, depending on the model year or aftermarket choice. The platform is flat and spacious, making it easy to get on and off the tractor during the day.
Noise Level (dB A @ Operator Ear)
Noise levels at the operator’s ear tend to be moderate to high compared to modern large tractors, as the ST55 is a compact utility model. When using the ROPS-only configuration, you can expect noise levels to be similar to most open-station tractors.
Hearing protection is recommended, especially during long operating periods. If you add a cab enclosure, noise is reduced thanks to the insulation in the headliner and roof.
For most operators, the sound inside the cab is still noticeable but more comfortable. All-day use is more tolerable.
Cab & Operator Station Features Table
| Feature | ROPS / Cab Option | Climate Control | Seat & Suspension | Noise Level (dB A @ Ear) |
|---|---|---|---|---|
| Standard | ROPS bar | None | Basic contoured seat | Moderate to high (ROPS) |
| Optional | Full cab enclosure (various brands) | A/C, Heater, Air filter | Upgraded padded or suspended seat | Lowered with cab installed |
| Access | Hinged/removable doors, wide step access | Internal control switches | Adjustable height/distance | Ear protection suggested |
| Comfort/Protection | Weather/dust shield in cab | Filters dust/pollen | Armrests on some models | Insulated cab reduces noise |
| Installation | Bolt-on design for cab, ROPS built-in | Pre-wired for add-ons | Flat operator platform | Standard across series |
Hydraulics
You get an open-center hydraulic system with the AGCO ST55 Tractor, delivering reliable performance for a variety of implements and attachments.
Understanding system type, pump flows, system pressure, and valve options can help you get the most from your hydraulic system.
Key features like implement pump flow and remote valve configuration play a big role in daily use and operation.
| Feature | Specification or Detail |
|---|---|
| System Type | Open-center |
| Implement Pump Flow | 11.4 L/min (approx. 3.01 gpm) |
| Steering Pump Flow | Not separately specified (uses single pump) |
| Total Combined Flow | 11.4 L/min (approx. 3.01 gpm) |
| System Pressure | 2276 psi (156.9 bar) |
| Remote Valves | 1 rear remote (configurable on some models) |
System Type (Open-Center / Closed-Center / PFC)
The AGCO ST55 uses an open-center hydraulic system.
In an open-center setup, hydraulics use a single pump and flow continuously through the system.
When you do not activate a hydraulic function, the oil flows back to the tank, reducing system pressure and lessening heat build-up.
Open-center systems are simple and easy to maintain.
You do not get flow-on-demand or pressure-on-demand controls like in closed-center or pressure-flow compensated (PFC) systems.
This approach works well for tractors like the ST55, which are designed for basic lifting, loader work, and operating simple implements.
Open-center hydraulics generally offer straightforward repairs and usually have lower service costs.
Implement Pump Flow (L min⁻¹)
Pump flow is a key figure for hydraulic performance.
For the AGCO ST55, the pump flow is 11.4 liters per minute (about 3.01 gallons per minute).
This flow rate is enough for running most small implements and attachments such as loaders, mowers, or rear-blade adjustments.
However, if you need to operate implements that demand high flows, this pump may be limiting.
Lower flow rates mean cylinders may move slower than on larger tractors.
For jobs like raising a loader or tipping a dump trailer, this level of flow is quite standard on compact and mid-sized utility tractors.
Steering Pump Flow (If Separate)
The ST55 does not have a separate steering pump.
Instead, power steering takes oil from the same hydraulic circuit used for the implements.
This setup is common in open-center tractors.
It keeps the system less complex and reduces parts without major downsides for basic farm use.
You may sometimes notice reduced steering power if you use a hydraulic attachment heavily at the same time, but for most tasks, the shared flow offers enough capacity.
Total Combined Flow
On the AGCO ST55, the total combined flow for both steering and implement use is 11.4 liters per minute.
Because both functions use oil from the same pump, the available flow splits among all hydraulic needs.
Steady overall flow works well for most farming chores, loader operations, and three-point hitch controls.
If you ever experience slower response while both steering and other hydraulic functions are used together, it comes from this flow-sharing arrangement.
System Pressure (bar / psi)
The hydraulic system on the ST55 operates at a maximum pressure of 2276 psi (156.9 bar).
System pressure controls how much force the hydraulics can apply to cylinders and motors.
Higher pressure allows you to lift heavier loads with smaller cylinders.
This level of pressure is common for tractors in this horsepower class, and it’s enough for tasks like loader work, running hydraulic mowers, or operating rear implements.
Pressure limits also protect hydraulic hoses and components from excessive stress.
Remote Valves (Number & Type)
The ST55 is equipped with at least one rear remote valve by default.
This valve allows you to connect hydraulic hoses from implements, such as a rear blade or post-hole digger.
Depending on configuration or optional equipment, the number and type of remote valves may be upgradable.
You may be able to add more valves if you need to operate attachments that need two-way flow or require multiple hydraulic outlets.
Remote valves are controlled by levers beside the seat.
They use quick-connect couplers for easy attachment and swapping of hoses.
| Subsection | Details |
|---|---|
| System Type | Open-center; single pump; continuous oil flow |
| Implement Pump Flow | 11.4 L/min (3.01 gpm); supports basic implements |
| Steering Pump Flow | No separate pump; steering shares flow with implements |
| Total Combined Flow | 11.4 L/min (3.01 gpm) for both implement and steering |
| System Pressure | 2276 psi (156.9 bar); suitable for loader and implement work |
| Remote Valves | 1 rear remote standard; additional remotes may be available option |
Three-Point Hitch (3PH)
The AGCO ST55 is equipped with a rear three-point hitch that improves the tractor’s flexibility for different farm tasks.
You can attach, lift, and control a wide variety of implements.
Hitch Category (1 / 1N / 2 / 3)
The AGCO ST55 uses a Category I three-point hitch.
Category I hitches are most common on compact and utility tractors, supporting implements for lighter to moderate work.
The pin diameter for Cat I is 7/8 inch for the lower arm and 3/4 inch for the top link.
You can use a wide range of compatible tools, including rotary mowers, tillers, spreaders, and rear blades.
The linkage arms have telescopic link ends, which make connecting attachments easier and faster.
Category I hitches can handle most of the jobs needed for small- to mid-sized farms.
Lift Capacity @ Ball Ends
The AGCO ST55 has a rear lift capacity of 3,086 lbs (1,399 kg) at the ball ends.
This rating is important because it tells you the maximum weight the hitch can safely lift near the implement’s attachment point.
This capacity supports heavier implements like box blades, small plows, spreaders, or medium-size rotary cutters.
Always check the implement’s weight and keep the total below the maximum lift rating, as attachments that are too heavy may cause unsafe handling or damage to the tractor.
Lift capacity at the ball ends also affects how much material you can move or manage with each pass.
Lifting heavier implements may reduce the steering’s response or overall balance, so proper ballast or weighting may be needed.
Draft / Position Control
The ST55 is equipped with position control on its three-point hitch.
Position control gives you the ability to set and maintain the exact height or depth of the attached implement.
This control is helpful when you want a tool, such as a mower or tiller, to run at a specific working height.
However, the ST55 does not include draft control as a standard feature.
Draft control automatically adjusts the hitch height to keep a consistent load, which is most useful for ground-engaging tools like plows.
Without draft control, you need to manually adjust the hitch if the load changes (for example, on uneven soil).
You should use position control for tasks that require accuracy in implement height.
If you work mostly with ground-engaging tools and need automatic adjustment, consider if draft control is necessary for your operation.
Top-Link Sensing (Yes/No)
The AGCO ST55 does not have top-link sensing on its three-point hitch.
Top-link sensing is a feature usually found on larger, more advanced tractors.
It allows the tractor to measure draft force through the top link, providing more precise automatic control for soil-working implements.
Without top-link sensing, hitch adjustments are made solely based on settings you choose, along with manual feedback.
While this is sufficient for mowing, grading, or carrying lightweight attachments, it does not offer automatic response during heavy tillage or plowing.
| Feature | Specification / Details |
|---|---|
| Hitch Category | Category I; 7/8″ lower link pins, 3/4″ top link pin |
| Lift Capacity | 3,086 lbs (1,399 kg) at ball ends |
| Linkage Features | Telescopic link ends for easier implement connections |
| Control Type | Position control (no draft control standard) |
| Top-Link Sensing | No |
| Best for Implements | Rotary mowers, tillers, rear blades, spreaders, box blades |
| Automatic Adjustments | Manual, via position control lever |
Axles & Load Limits
The AGCO ST55 is designed to perform a wide range of tasks, and understanding its axle and load limits helps you safely manage its capabilities.
Knowing the specifics for front-axle load, rear-axle load, and final-drive type ensures you get the best performance and durability.
| Specification | Value | Details/Notes |
|---|---|---|
| Maximum Front-Axle Load | Not specified | Not provided by AGCO or data sources |
| Maximum Rear-Axle Load | Not specified | Not provided by AGCO or data sources |
| Rear Lift Capacity (at ends) | 1,399 kg | 3,086 lbs, measured at link ends |
| Final-Drive Type | Not detailed | Data not released by manufacturer |
| Rear Arms | Telescopic | For easier implement attachment |
| Clutch | Electro-hydraulic | For smooth power transfer |
Maximum Front-Axle Load (kg)
The official maximum front-axle load for the AGCO ST55 is not published in available sources.
In practical terms, this means you must use caution when adding front-mounted implements or weights.
Exceeding the front-axle limit risks structural damage and unsafe handling.
Always distribute loads evenly and follow industry best practices.
If you plan to use a front loader or heavy front implements, consider weighing the tractor for balance and monitoring tire pressures.
Regularly inspect the front axle for wear, especially if using the unit for loader work or heavy field operations.
Consult with your AGCO dealer for recommended loading guidelines if exact specifications are needed for your application.
Maximum Rear-Axle Load (kg)
The ST55’s exact maximum rear-axle load is also not listed by the manufacturer.
What is published is the rear lift capacity at the link ends, rated at 1,399 kg (3,086 lbs).
This figure represents how much weight the three-point hitch can safely manage at its ends.
When using rear-mounted implements like plows or rotary cutters, keep within this limit to avoid overloading the hydraulic system and the rear axle.
Overloading the rear can contribute to premature wear or component failure.
It’s also important to consider total implement weight and cargo, not just point load on the hitch.
Spreading the load and using ballast when appropriate can help maintain stable, safe operation.
Final-Drive Type
Details about the ST55 final-drive system are not published in manufacturer data.
Most tractors in its class use robust gear or planetary final drives to transfer power from the transmission to the wheels.
These systems are built to handle regular stress from pulling attachments and driving over varied terrain.
Regular fluid maintenance and inspection help preserve the integrity of your final drive over years of operation.
The rear wheel arms on the ST55 are telescopic, making it easier to attach implements and adjust track width when needed.
The electro-hydraulic clutch ensures smooth power transfer, supporting long-term durability in the drivetrain.
Tires & Track Options
The AGCO ST55 offers a choice of tire sizes and types to match your work needs, with options for both front and rear wheels.
For specialized tasks, you also have a range of upgrades including dual wheels, tracks, and flotation kits.
Standard Front Tire Size (Ag / Turf / Industrial)
The AGCO ST55 typically comes with 7.5-16 agricultural (Ag) tires on the front.
These provide solid traction and work well for plowing or fieldwork.
If you use the tractor mostly on finished lawns or softer ground, you might switch to turf tires in a similar size, which are gentler on grass and reduce soil disturbance.
For construction or mixed-use areas, industrial tires are sometimes offered.
These provide a balance between grip and wear, and they can handle harder surfaces like gravel.
The tractor can also be fitted with 35×12.00-16.5-sized front tires as another Ag option, offering more float and stability in certain conditions.
Standard Rear Tire Size
Rear tires on the AGCO ST55 are usually 13.6-28 Ag tires, built for traction and weight distribution.
These are ideal for heavy fieldwork and help transfer the tractor’s 55 hp to the ground efficiently.
You might see other sizes like 14.9-28 as options, which offer a slightly wider footprint and better flotation in soft soils.
If you need less ground disturbance, such as when mowing large lawns, turf versions of the rear tires are available.
Turf tires offer a smoother ride and prevent rutting.
Industrial rear tires are not as common but may be possible by special order.
Matching front and rear tire types is important for best stability and performance.
Optional Duals / Tracks / Flotation Kits
For extra traction in muddy or soft fields, you can fit dual rear wheels on the AGCO ST55. Duals provide more grip and reduce soil compaction, making them useful for tillage or heavy pulling.
It is important to use proper spacers and follow manufacturer guidelines to avoid stress on the axles. Track options can be used for very wet or loose soils, where even duals might not be enough.
While not factory standard, third-party kits such as rubber tracks can be installed for enhanced flotation and reduced ground pressure. If you frequently work on soft or delicate surfaces, flotation kits—which use extra wide tires or low-pressure tires—are another way to minimize soil damage.
The table below summarizes the main tire and track choices:
| Option Type | Size/Type | Best Use Case | Notes |
|---|---|---|---|
| Front Tire (Standard) | 7.5-16 (Ag) | Field work, general traction | Good for most Ag tasks |
| Front Tire (Alt.) | 35×12.00-16.5 (Ag) | Improved flotation or stability | Larger tire for specific conditions |
| Front Tire (Turf) | Varies (Turf) | Grass, lawns | Reduces turf damage |
| Front Tire (Industrial) | Varies (Industrial) | Mixed or hard surfaces | Better wear and durability |
| Rear Tire (Standard) | 13.6-28 (Ag) | Field work, heavy pulling | Standard rear tire |
| Rear Tire (Alt.) | 14.9-28 (Ag) | Looser soils | Wider, more flotation |
| Rear Tire (Turf) | Varies (Turf) | Grass, lawns | Prevents ruts, gentler on ground |
| Dual Rear Wheels | 2x standard per side | Max traction, reduced compaction | Requires spacers/stability check |
| Track Kits | Rubber tracks | Wet, loose, or sensitive soils | Aftermarket, offers lowest ground pressure |
| Flotation Kits | Extra-wide/low-pressure tires | Soft or marshy soil | Low soil impact, may reduce traction in hard ground |
Dimensions & Weight
The AGCO ST55 tractor has a sturdy build with specific measurements that affect both operation and transport. Features like wheelbase, length, width, and weight all impact its handling, stability, and usability in different working environments.
Wheelbase
The wheelbase of the AGCO ST55 is 78.9 inches (200 cm). This distance, measured from the center of the front wheel to the center of the rear wheel, helps balance the tractor and affects turning radius.
With this wheelbase, you get stable performance, even when carrying heavy loads or using larger implements. A longer wheelbase provides more stability on uneven ground, which helps if you work on hills or rough terrain.
The 78.9-inch distance also aids in smoother rides by distributing weight evenly. You can expect less bouncing and better control, especially if driving at higher speeds or with attachments.
The design choice in wheelbase for the ST55 means good maneuverability without sacrificing steadiness. This is useful for field work and tasks that require tight turns, like working around buildings or in confined farmyards.
Overall Length
The overall length of the AGCO ST55 is 137 inches (347 cm). This includes the full distance from the front to the rear, not counting any special attachments or front weights you might use.
The length is a key factor in transport and storage planning. With a length of 137 inches, you have a tractor that is long enough for stability but still manageable in size.
You can store it in most standard barns or sheds without trouble. It is helpful to consider this measurement if you routinely park multiple vehicles or have limited indoor space.
The length also helps with weight distribution. It lets you use larger attachments at the back and mount tools at the front without making the machine feel off balance.
You do not need much extra room for basic attachments like loaders or rear implements, making the AGCO ST55 practical for most small to mid-size farms.
Overall Width (Minimum Tread)
The minimum overall width—measured at the narrowest tread setting—is 72.7 inches (184 cm). This measurement is without any extra wheel spacers or wide-set tires.
Having a minimum width of 72.7 inches lets you move through tight pathways and gates. This is important when working between crop rows or traveling down narrow farm lanes.
The width also makes it easier to transport the tractor on trailers, since it can fit standard loading widths. If you work on hilly terrain, you may want to set the wheels wider for more stability, but the minimum width is ideal for row-crop farming or greenhouse use.
This makes the ST55 versatile if you need a tractor that fits both larger, open fields and more confined plots.
Height To ROPS / Cab
The height to the top of the ROPS (Roll-Over Protective Structure) is 98.8 inches (250 cm) when raised. If you fold the ROPS, the tractor’s height drops to 75.5 inches (191 cm).
Some models may offer a cab, but most AGCO ST55 tractors come with an open station and ROPS. A maximum height of 98.8 inches can clear most standard doors and low-hanging branches, as long as you check before entering tight spaces.
Folding down the ROPS to 75.5 inches helps if you need to store your tractor in a low garage or transport it under bridges. The ROPS is critical for operator safety, and having the option to fold it down without removing it makes everyday use simpler.
This feature is especially helpful if you switch between field work and storage often.
Ground Clearance
Ground clearance for the AGCO ST55 is typically about 16 to 17 inches (approximately 40-43 cm). This space beneath the tractor frame helps protect it from rocks, stumps, or debris.
With more than 16 inches of clearance, you can work in rough fields without scraping the undercarriage. This is useful for tilling or mowing areas with uneven surfaces.
The clearance also helps if you must cross ditches or ridges, common in pasture maintenance. If you use the ST55 in orchard or vegetable farming, high ground clearance means less risk of damaging plants or getting stuck.
This measurement, combined with the robust tires, lets you work confidently in different field conditions.
Shipping Weight
The shipping weight of the AGCO ST55 is 4,417 pounds (2,003 kg). This is the weight of the tractor as delivered from the factory, without fluids like fuel and coolant or extra equipment.
Knowing the shipping weight is important when arranging transportation, especially by trailer. At just over 4,400 pounds, the ST55 is not overly heavy for loading onto standard farm trailers or for delivery by commercial trucks.
The manageable weight makes it less likely to exceed most local road limits for farm equipment. This also means you can use most standard towing equipment, without the need for heavy-duty machinery.
Always check the combined weight if you plan to add front loaders, ballast, or attachments, as these will increase the overall load.
Operating Weight (With Fluids)
The operating weight—filled with standard fluids such as oil, fuel, and coolant—of the AGCO ST55 is typically a bit higher than its shipping weight. An estimated operating weight is around 4,600 to 4,700 pounds (2,086 to 2,132 kg), though this can vary depending on additional equipment.
Operating weight better reflects real working conditions. When you fuel the tractor, add coolant, and fill the hydraulic systems, the extra weight can affect both performance and towing requirements.
This number is especially important if you use the tractor for jobs that require maximum stability, such as loader work or towing. It ensures you know the full weight impacting your ground, trailer, or implements, so you can make safe and efficient choices.
AGCO ST55 Tractor: Dimensions & Weight Overview
| Aspect | Measurement | Notes |
|---|---|---|
| Wheelbase | 78.9 in (200 cm) | Stable for field and loader work |
| Overall Length | 137 in (347 cm) | Allows balanced attachment use; manageable storage |
| Overall Width (Min.) | 72.7 in (184 cm) | Helps navigate narrow areas |
| Height to ROPS (Raised) | 98.8 in (250 cm) | Maximum safe height with ROPS upright |
| Height to ROPS (Folded) | 75.5 in (191 cm) | Fits low-ceiling spaces |
| Ground Clearance | ~16–17 in (~40–43 cm) | Suited for rough fields and crops |
| Shipping Weight | 4,417 lbs (2,003 kg) | Factory-delivered, no fluids |
| Operating Weight (With Fluids) | 4,600–4,700 lbs (2,086–2,132 kg) | Estimated; varies based on added equipment |
Fuel & Fluids
Proper fuel and fluid management is essential for reliable operation and long engine life. Knowing exact capacities and specifications allows you to maintain your AGCO ST55 tractor correctly and avoid downtime.
Fuel-Tank Capacity
The AGCO ST55 tractor features a robust diesel fuel system with indirect injection. Its fuel tank capacity is 12.7 gallons (48.1 liters), letting you work for long periods before you need to refuel.
This size is typical for a tractor of this horsepower, balancing machine weight and work time. With your 4-cylinder, liquid-cooled Iseki diesel engine, proper diesel fuel is required.
Always use clean, fresh diesel rated for off-road use, and be sure the tank is checked for water or debris buildup. Fuel filters should also be replaced regularly to ensure consistent flow and performance.
DEF-Tank Capacity (If Applicable)
The AGCO ST55 does not have a Diesel Exhaust Fluid (DEF) system. DEF systems are sometimes found on newer, higher-horsepower tractors to meet emissions regulations, but the ST55 was built without this technology.
This means you do not need to refill or maintain a DEF tank. Because there is no DEF system, you save time during maintenance and can focus on standard diesel fuel-care and engine upkeep.
There are no warning lights, tank heaters, or fluid sensors related to DEF on the ST55.
Engine Oil Capacity
Engine oil is critical to cooling, lubrication, and preventing engine damage. The engine oil capacity for the AGCO ST55 is around 2.7 gallons (10.2 liters).
AGCO recommends using a high-quality diesel engine oil of the correct viscosity, like 15W-40, especially in varied temperatures. To maintain proper oil quality, change the engine oil and filter at the intervals suggested in your owner’s manual.
Always check for leaks or unusual oil drop. Make sure to use oils that meet or exceed the manufacturer’s standards to keep the engine running smoothly and extend engine life.
Hydraulic/Transmission Oil Capacity
The hydraulic and transmission system share a common reservoir in the AGCO ST55. The total combined capacity for hydraulic and transmission oil is about 9.8 gallons (37 liters).
Using the correct type of oil is important for smooth shifting, efficient hydraulic response, and reduced component wear. Make sure the fluid is topped up to the specified level.
Check the fluid for signs of contamination, such as milky color, which can suggest water ingress. Hydraulic filters must be replaced as recommended.
Clean oil in hydraulics and the transmission prevents costly failures and maintains accuracy in 3-point hitch and loader functions.
Table: AGCO ST55 Fuel & Fluid Capacities
| System | Capacity | Type/Spec | Notes |
|---|---|---|---|
| Diesel Fuel Tank | 12.7 gal (48.1 L) | Off-road diesel | Check for contaminants, replace filters |
| DEF Tank | Not applicable | N/A | ST55 does not require DEF |
| Engine Oil | ~2.7 gal (10.2 L) | 15W-40, meets spec | Change with filter per manual |
| Hydraulic/Transmission Oil | ~9.8 gal (37 L) | Tractor hydraulic/trans. | Check regularly, replace filters as needed |
Electrical System
You will find that the AGCO ST55 is equipped with a practical and straightforward electrical system. It supports key functions like starting, charging, and vital controls required for daily tractor use.
| Subtopic | Typical Specification | Details |
|---|---|---|
| Ground Type | Negative | One 12-volt negative ground battery, common in modern tractors. |
| Alternator / Charging System | Alternator | Maintains battery charge and powers electrical systems; exact alternator type may vary. |
| Charging Output (Amps) | Not Specified / Usually 40-60 Amps | Delivers enough current for starting and running all electrical components. |
| Battery Voltage | 12 Volts | Supports engine start and all standard accessories. |
| Battery CCA Rating | Not Specified / Commonly 550-700 CCA | Sufficient cold cranking amps for reliable starts in a range of temperatures. |
Ground Type (Negative / Positive)
AGCO ST55 tractors use a 12-volt battery system with a negative ground configuration. This means the negative terminal of the battery connects to the tractor’s chassis.
Negative ground is standard in most modern tractors and vehicles. It helps in preventing electrical shorts and makes routine troubleshooting simpler.
You should always connect jumper cables and battery chargers with the correct polarity to prevent electrical damage. Using a negative ground system also supports the safe functioning of all electronic and lighting systems installed on the ST55.
Most electrical components, such as the starter, lights, and instrument cluster, are designed to work with this grounding type. If you add new electrical accessories or perform maintenance, always verify that everything matches the negative ground layout.
Alternator / Charging System
The AGCO ST55 uses an alternator as its charging system. The alternator is responsible for keeping the battery charged while the engine is running.
It converts mechanical energy from the engine into electrical energy for the tractor. This system supplies power to electrical parts like headlights, work lights, and control panels.
The alternator operates at standard engine speeds, ensuring stable power even with several accessories running. Important connections from the alternator include leads to the battery terminal and regulation circuits.
The alternator is typically maintenance-free but may need periodic checks for belt tension or physical wear.
Charging Output (Amps)
The specific charging output in amperes (amps) for the AGCO ST55 is not detailed in public sources. Many tractors in this class use alternators rated between 40 and 60 amps.
Higher amp output means the alternator can quickly recharge the battery and power more electrical accessories. This is important for tasks involving extended lighting use, additional work lamps, or auxiliary electronics.
If your tractor’s alternator output seems low, you might notice dimming lights, slow cranking, or issues with electronic attachments. Routine inspections can identify problems with output or wiring, which should be addressed quickly to avoid dead batteries.
To check output, measure voltage at the battery terminals with the engine running. If it’s lower than 13.5 volts, the alternator may not be charging correctly.
Battery Voltage
The AGCO ST55 runs on a 12-volt battery system. This voltage level is standard for compact utility tractors and supports the starter motor, fuel solenoid, lights, and other electrical accessories.
A properly charged 12-volt battery reads about 12.6 volts when fully charged and at rest. When the engine is running and the alternator is working, voltage at the battery should read between 13.5 and 14.5 volts.
Most replacement and accessory parts for the ST55 are matched to the 12-volt system. Never use a battery or electrical component rated for a different voltage, as this can cause electrical damage or issues with starting.
If you experience hard starts or dim lights, check battery voltage with a multimeter. Low readings could mean battery age, damage, or issues with the charging system.
Battery CCA Rating
While the exact Cold Cranking Amps (CCA) rating for the AGCO ST55’s battery is not clearly specified, it commonly falls in the 550-700 CCA range for similar 55-horsepower tractors.
CCA is critical for starting the engine, especially in colder climates or after long periods of inactivity. Higher CCA ratings provide stronger and more reliable cranking.
When choosing a replacement battery, always match the required physical size, terminal location, and CCA rating suitable for your climate. Too low a CCA value may cause hard starting or failed starts in winter.
Maintenance tips include keeping battery terminals clean, checking water levels in non-sealed batteries, and storing batteries indoors during extreme cold.
Total Cost Of Ownership Metrics
Owning an AGCO ST55 tractor involves steady costs for service, parts, fuel, and depreciation. Understanding these specific factors helps you plan your budget and keep your tractor working reliably.
Recommended Service Intervals
You need to follow the service intervals set out in the manufacturer’s guide to keep your AGCO ST55 running well. In general, engine oil and filter changes are required every 100 hours of operation.
Hydraulic oil and filter service is needed every 300 hours. Air filters should be checked and cleaned or replaced every 50-100 hours, depending on dust conditions.
Fuel filters should be changed every 200 hours. Coolant needs attention every 600 hours or once a year.
Transmission oil and final drive fluids should be replaced every 600 hours. Sticking to these intervals helps prevent breakdowns and expensive repairs.
| Service Item | Interval (Hours) | Notes |
|---|---|---|
| Engine Oil & Filter | 100 | Change more if dusty |
| Hydraulic Oil/Filter | 300 | Only AGCO-approved fluids |
| Air Filter | 50-100 | Check frequently |
| Fuel Filter | 200 | Use clean diesel |
| Coolant | 600 (or yearly) | Check for leaks |
| Transmission Oil | 600 | Replace filter too |
Estimated Annual Maintenance Cost
Yearly maintenance costs can depend on how much you use your tractor and local labor rates. For typical use, expect to pay around $500 to $1,000 each year for routine maintenance.
This includes oil changes, filters, inspections, and basic repairs. If you use your tractor heavily or need more repairs, these costs may be higher.
Parts like filters and fluids, along with small items such as belts or hoses, make up the main part of the yearly cost. Labor for scheduled service adds more, especially if you take your tractor to a dealer.
Rare but larger repairs, such as replacement of a hydraulic pump, increase costs in years when they are needed.
| Item | Estimated Annual Cost (USD) |
|---|---|
| Oil & Filter Changes | $150 |
| Hydraulic/Transmission Oil | $100 |
| Air & Fuel Filters | $80 |
| Labor/Inspection | $200 |
| Misc. Parts (belts, hoses) | $100 |
| Total (approx.) | $630 |
Depreciation Curve (% Per Year)
Tractor depreciation is important for understanding resale value. The AGCO ST55, bought new, loses about 15% of its value in the first year.
After that, depreciation slows and averages 7-10% per year for the next few years. By year five, many ST55s retain about 55-60% of their original value if kept in good condition and serviced on time.
Keeping records, proper storage, and regular maintenance help hold the value over time. Market demand, hours of use, and visible wear can speed up or slow depreciation.
Trade-in or selling privately affects the price you are likely to receive.
| Year | % Value Remaining | Notes |
|---|---|---|
| 1 | 85% | Most rapid drop |
| 2 | 77% | |
| 3 | 70% | |
| 4 | 63% | |
| 5 | 55-60% | Good condition assumed |
Fuel Consumption @ Rated Load (L hr⁻¹)
The AGCO ST55 uses a 55.6 hp engine. When running at full load, it consumes about 7 to 8 liters of diesel fuel each hour.
This rate is typical for tractors in this size range. Light work, such as idling or slow operation, uses less fuel—often 4 to 5 liters per hour.
Fuel cleanliness and engine condition can slightly change those numbers. Using clean diesel and maintaining engine filters helps keep consumption at the lower end.
High workloads or running the tractor at full power for long periods will keep consumption near the maximum rate.
| Operating Condition | Fuel Use (L/hr) | Notes |
|---|---|---|
| Maximum Rated Load | 7 – 8 | Approximate, varies by task |
| Light/Moderate Load | 4 – 5 | Lower stress, less fuel |
| Idle | 1 – 2 | Minimal engine work |