AGCO ST33A Tractor 33 hp Overview, Specs, and Performance
AGCO ST33A Tractor 33 hp
The AGCO ST33A tractor is built with a 33 horsepower (hp), 3-cylinder, liquid-cooled diesel engine made by Iseki. This engine uses an indirect injection fuel system and reaches its peak power at 2600 RPM.
With 33 hp gross engine power, you get about 25.9 hp PTO (Power Take-Off) power. This means the tractor can operate a variety of implements and attachments suited for farming, landscaping, and property maintenance.
The ST33A uses a 91 cubic inch (1,491 cc) engine displacement, giving you solid performance for a compact utility tractor. The engine starts with a 12-volt electric starter, making it easy to operate.
You will find that the wheelbase is compact for maneuverability, measured at 5.47 feet. Standard AG R1 tires provide reliable traction in different conditions.
Below is a summary of key specifications:
| Feature | Specification |
|---|---|
| Engine Power | 33 hp |
| PTO Power | 25.9 hp (claimed) |
| Engine Type | 3-cylinder diesel (Iseki) |
| Displacement | 91 cu in (1,491 cc) |
| Fuel System | Indirect injection |
| Rated RPM | 2600 |
| Starter | Electric, 12-volt |
| Wheelbase | 5.47 ft |
| Tire Type | Ag R1 |
This layout gives you reliable power and solid build quality. The simple controls and compact size make it a versatile choice for many types of property work.
Production & Identification
The AGCO ST33A is a 33-horsepower compact utility tractor produced in the mid-2000s. It is recognized for its reliable Iseki diesel engine and strong construction, making it popular among small farmers and property owners.
Manufacturer / Brand
You will find that the AGCO ST33A tractor is a product of collaboration between AGCO Corporation and the Japanese manufacturer Iseki. AGCO, a major agricultural equipment company based in the United States, is the distributor and marketer of this model under its brand.
The actual manufacturing was completed by Iseki, a respected company in Japan with a long history in building compact tractors. This partnership led to the release of several compact utility tractors, including the ST22A, ST24A, ST28A, and ST33A.
Iseki’s engineering ensures quality and reliability, while AGCO’s support network covers sales and service in North America and other regions. The ST33A was sometimes cross-listed with other AGCO-related models, such as the Challenger MT255B, which shared similar components and specifications.
Model Number / Series
The ST33A belongs to the AGCO ST-A series, which included several compact tractors designed for productivity and versatility on small farms and properties. Other models in this series are the ST28A, ST22A, and ST24A, each denoting different horsepower and size classes.
You may also see references to ST25, ST30X, ST32, ST34A, and ST41A when researching AGCO’s compact tractor lineup. The ST33A sits near the top in terms of power for its class.
Its model designation (“ST33A”) indicates a 33-horsepower rating and its place within the series. This model is known for a hydrostatic transmission and compatibility with a wide range of implements.
Factory of Manufacture
All ST33A tractors were built at Iseki’s main manufacturing facility in Matsuyama, Japan. This factory is known for producing robust, precision-engineered compact tractors for both the Japanese and global markets.
The Matsuyama plant is equipped with advanced machinery and follows strict quality control processes. Models built here were exported for AGCO and also rebranded under other names, depending on the market.
Years Produced
Production of the AGCO ST33A ran from 2005 to 2008 as part of AGCO’s effort to expand their compact tractor line in North America. These years mark the main era for the ST-A series, which also included the ST28A, ST22A, and other similar models.
If you are looking for one on the used tractor market, models from this period make up the available inventory. By 2008, new AGCO compact models began to phase out the ST33A, and sometimes it was replaced by similar Iseki-based or Challenger models sold through AGCO’s dealer network.
Original List Price (Launch Year)
At launch in 2005, the original list price of the AGCO ST33A was competitive for its segment. The price placed it in the mid to upper range of compact utility tractors, largely due to its features, horsepower, and hydrostatic transmission.
Exact pricing varied by dealer, region, and included options. Sources indicate that the base price was typically in the area of $17,000 to $20,000 USD when new.
Optional features such as loaders, rear implements, or turf tires could increase the cost further. Today, resale values depend on condition, usage hours, and included equipment.
Serial-Number Location
The serial number for your AGCO ST33A tractor is found on a metal identification plate. This plate is usually located on the left side of the tractor frame, above or near the front axle.
Checking the serial number is useful when verifying a unit’s year of manufacture, ordering parts, or confirming service history. For best results, clean the area with a cloth to ensure the serial number is fully visible.
The plate contains not only the serial number but often additional information, such as manufacturing date and model code. You should always record your tractor’s serial number for reference and insurance purposes.
| Topic | Details |
|---|---|
| Manufacturer / Brand | AGCO (Distributor, USA); Iseki (Manufacturer, Japan) |
| Model Number / Series | ST33A; Part of the ST-A Series (includes ST22A, ST24A, ST28A, etc.) |
| Factory of Manufacture | Matsuyama, Japan (Iseki Production Facility) |
| Years Produced | 2005–2008 |
| Original List Price | Approx. $17,000–$20,000 USD (2005 base model); price varies with options |
| Serial-Number Location | Metal plate on left side of tractor frame, near front axle |
Engine Specifications
The AGCO ST33A uses a diesel engine designed for reliability and fuel efficiency. Its 3-cylinder engine produces a balance of power and smooth performance, while key technical details like displacement, horsepower, and cooling help you understand what to expect during operation.
| Attribute | Details |
|---|---|
| Engine Make & Model | Iseki, 3-cylinder |
| Fuel Type | Diesel |
| Emissions Tier | Not officially specified |
| Displacement | 1.5 L (91.4 cu in) |
| Cylinders | 3 |
| Rated Gross Horsepower | 33 hp (24.6 kW) |
| Net PTO Horsepower | 25.9 hp (19.3 kW) |
| Peak Torque | Information not available |
| Compression Ratio | Information not available |
| Cooling System | Liquid-cooled |
| Cooling Capacity | Information not available |
Engine Make & Model
The engine in your AGCO ST33A is manufactured by Iseki, a well-known Japanese company. It uses a 3-cylinder configuration, which is common for compact tractors that need efficiency and manageable power.
Iseki engines have a reputation for durability and smooth operation. The 3-cylinder design helps the tractor stay efficient on fuel while still offering enough muscle for heavy field tasks.
These engines also reduce vibration compared to single or twin-cylinder engines. Iseki’s engineering ensures reliability for frequent use.
This means fewer problems over time, provided you follow regular maintenance schedules. The engine is also compact, so it fits within the tractor’s small frame without sacrificing accessibility for repairs and service.
Fuel Type & Emissions Tier
The AGCO ST33A uses diesel fuel. Diesel engines are standard in tractors due to their strong low-end torque and fuel efficiency.
The emissions tier is not specifically listed for the ST33A. Older compact tractors like this usually meet pre-Tier 4 emissions standards.
This means emissions controls are basic, relying mostly on engine tuning rather than on advanced catalytic systems. You may notice less electronics and after-treatment compared to newer models.
However, you should still follow local regulations for diesel equipment and be aware that emissions may be higher than newer, stricter tier models.
Cylinders / Displacement
This engine features 3 cylinders and has a displacement of 1.5 liters (91.4 cubic inches). Three cylinders provide a good mix of power, balance, and smoothness.
The engine’s displacement determines its total capacity to draw in air and fuel, affecting both potential power and torque. 1.5 liters is a common size for compact utility tractors.
This displacement allows enough power for tough jobs—such as loader work or running implements—without making the tractor overly heavy. More cylinders and higher displacement usually mean smoother running and better power pulses, especially noticeable while hauling.
The smaller bore and stroke (cylinder size and movement) help keep fuel use low during lighter work. This design also reduces vibration and wear.
Rated Horsepower (Gross & Net)
The gross engine power rating for the AGCO ST33A is 33 horsepower (24.6 kW). Gross power means what the engine produces before power is used by other systems, such as the water pump, fan, or alternator.
PTO (Power Take-Off) horsepower, which is the amount actually available to attachments, is rated at 25.9 hp (19.3 kW). This difference shows the energy lost through drivetrain components, which is normal for tractors.
This level of horsepower suits mowing, tilling, loader work, or snow removal. Always match the PTO rating, not just engine horsepower, to the attachment you plan to use.
Peak Torque (Nm @ rpm)
Detailed information about peak torque and at which rpm it is achieved is not directly listed for the AGCO ST33A. However, most 1.5L, 3-cylinder diesel engines in this class deliver good torque at low rpm—as is typical for tractors.
Diesel engines produce higher torque at lower engine speeds compared to gas engines. You can expect strong pulling power even when the engine isn’t running at high speeds.
If you need exact torque values, you would likely reference technical service manuals or test the engine under load with a dynamometer.
Compression Ratio
The specific compression ratio for the ST33A’s Iseki engine is not listed in available sources. Most small, naturally aspirated diesel tractor engines have compression ratios between 17:1 and 22:1.
A high compression ratio in diesels squeezes the air-fuel mixture more tightly, increasing engine efficiency and power output. This also helps produce the strong low-end torque diesels are known for.
With diesel engines, higher compression requires sturdy construction, which is why the Iseki’s build quality is important for long life and durability. Always use the correct grade of diesel fuel to support optimal compression performance.
Cooling System & Capacity
The AGCO ST33A is equipped with a liquid-cooled system. This system uses a radiator, coolant, water pump, and hoses to keep engine temperature within safe limits.
Liquid cooling is more effective than air cooling for modern engines, especially under heavy loads or in hot weather. A liquid-cooled engine remains more consistent in temperature, which helps preserve engine life and prevents overheating.
The coolant passes through the engine block and radiator, transferring heat away efficiently. The exact coolant capacity isn’t published, but for 1.5L diesel tractor engines, it’s usually about 4-6 quarts (3.8-5.7 liters).
Always check the owner’s manual for the correct coolant type, as using the wrong one can cause corrosion or overheating. Regularly check coolant levels and condition to avoid engine damage.
Power Take-Off (PTO)
The PTO system on the AGCO ST33A allows you to run attachments like mowers, tillers, and even a backhoe. Understanding the horsepower, PTO type, and speed options helps you get the most from your implements.
| Topic | Details |
|---|---|
| Claimed PTO Horsepower | Around 24.5 hp (varies with transmission type) |
| PTO Type | Independent PTO (rear and mid) |
| PTO Speeds | Rear: 540 rpm, Mid: 2000 rpm |
| Rear PTO Shaft Size | 1.375 inch (standard 6-spline) |
| Rear PTO Use Cases | Mowers, tillers, balers, backhoe |
| Mid PTO Use Cases | Mid-mount mowers, snow blowers |
Claimed PTO Horsepower
The AGCO ST33A tractor has a main engine power rating of 33 hp. The amount of horsepower that reaches the PTO is typically less than the engine’s total output.
You get an estimated 24.5 hp at the PTO when using the hydrostatic transmission model. Some slight variations may occur with different transmission options.
Common attachments include rotary mowers, tillers, and even small backhoes. Having close to 25 PTO hp means you have plenty of strength for tough jobs without overloading the tractor.
PTO Type (Independent / Live / Economy)
The AGCO ST33A is equipped with independent PTOs on both the rear and mid positions. With an independent PTO, you can engage or disengage the PTO shaft without having to stop or clutch the tractor.
Both rear and mid PTOs are controlled with their own levers or switches. This gives you flexibility to run equipment like a mower on the mid PTO and a tiller or backhoe on the rear PTO.
You can also power implements while the tractor is stopped or idling. Independent PTO systems are preferred when using attachments that need to be switched on and off quickly or separately from the tractor’s movement, such as a post hole digger or a backhoe.
PTO Speeds (540 / 1 000 rpm)
The rear PTO operates at 540 rpm, which is the most common speed for agricultural implements. Most mowers, balers, and tillers are designed for this speed, ensuring compatibility with standard tools.
The mid PTO runs at 2000 rpm. This higher speed is useful for certain attachments, mostly mid-mount mowers and snow blowers.
There is no 1,000 rpm PTO option on the ST33A, which is typical for tractors in this size range. The standard 540 rpm and 2000 rpm options cover almost all popular attachments, including a compact backhoe attachment when using the rear PTO.
Always check your implement’s requirements to match the correct PTO speed and connection.
Transmission & Drivetrain
You get a hydrostatic transmission system that delivers easy control, flexible speeds, and smooth operation. The drivetrain setup also features selectable four-wheel drive and a differential lock for better traction and versatility in different field or yard environments.
Transmission Type (Syncro, Powershift, CVT, HST)
The AGCO ST33A uses a hydrostatic transmission (HST), which means you manage your speed and direction with simple foot pedal control instead of shifting gears. HST delivers smooth and continuous transitions between speeds.
This type of transmission is well-suited for tasks that require frequent speed changes, such as loader work or mowing. You can easily go forward and reverse without clutching.
Hydrostatic transmissions also need less maintenance compared to many gear-based systems. Operators enjoy reduced fatigue since there isn’t a repetitive need to shift or use the clutch.
Number of Gears / Ranges
Instead of traditional gears, your ST33A features multiple speed ranges in the hydrostatic transmission. Typically, you get three ranges: Low, Medium, and High, each managed with a simple selector.
- Low Range: Best for high-torque tasks like tilling or digging.
- Medium Range: Suitable for everyday tasks or moderate speeds.
- High Range: Used when you need faster travel across open ground.
This design allows for continuous variation of ground speed within each range. You do not have to stop and shift gears, making your work more efficient and comfortable.
Range selection is straightforward, requiring only a lever adjustment before you get started.
Top Transport Speed
With the hydrostatic transmission and proper range selection, the AGCO ST33A can reach maximum transport speeds between 12 and 15 mph (about 19–24 km/h) depending on tire size and other conditions.
This speed is useful when you need to move quickly between fields or along the road. Keep in mind that the actual top speed may vary, especially if you have heavy attachments or are traveling on uneven terrain.
When operating at top speed, always take care with heavy implements and use proper safety equipment.
Drive (2WD / 4WD / AWD)
The ST33A comes standard with selectable four-wheel drive (4WD). You decide when to engage 4WD based on ground conditions and the work at hand.
- 2WD Mode: Use for dry, flat surfaces to save fuel and reduce tire wear.
- 4WD Mode: Engage when you need extra traction for slippery, wet, or uneven ground.
Four-wheel drive improves traction in mud, loose soil, or snowy areas. It also increases pulling power for implements.
Switching between drive modes is handled by a lever or switch within easy reach. You don’t get all-wheel drive—it’s specifically selectable 4WD, giving you flexibility for various tasks and terrain.
Differential-Lock & Final Drives
A differential lock is included on the ST33A. When activated, it locks both rear wheels together so they turn at the same speed, preventing wheel spin in slippery places.
You engage the differential lock with a foot pedal or lever located near the operator platform. This feature is valuable when working in mud, snow, or loose soil where regular traction may be lost.
The final drives are sturdy and designed for durability in heavy field work. They transfer power from the transmission to the wheels effectively and with minimal maintenance needs.
| Feature | Details |
|---|---|
| Transmission Type | Hydrostatic (HST), foot pedal controlled |
| Gears/Ranges | 3 Ranges (Low/Medium/High), infinite speeds within each |
| Top Transport Speed | 12–15 mph (19–24 km/h), varies by tires and conditions |
| Drive | Selectable 2WD / 4WD |
| Differential-Lock | Standard, pedal/lever-activated for extra traction |
| Final Drives | Heavy-duty, low-maintenance |
Steering & Brakes
The AGCO ST33A features a power steering system and wet disc brakes designed for reliability and operator comfort. The steering and braking components are important for safety, stability, and effective maneuvering in a range of working conditions.
Steering System (Hydrostatic / Power-Assisted / Mechanical)
The AGCO ST33A uses a power steering system, giving you smooth and easy control with minimal effort. This system is hydraulic-based, so it helps reduce fatigue during long hours of operation.
The hydraulic pump assists in turning, making it simple to adjust direction even when carrying heavy loads or using attachments. You’ll find the steering is responsive, with very little play.
This improves your ability to navigate tight spaces around barns, fields, or equipment. Power steering is especially useful if you often operate the tractor with front-end loaders or other front-mounted implements.
For added durability, the steering system is built with robust components. Maintenance requirements are low, but regular checks on fluid levels and hoses ensure long life.
In cold weather, the hydraulic fluid may thicken, but the system is designed for all-season use.
Turning Radius (With Brakes)
The ST33A is designed with a compact wheelbase, so it offers a tight turning radius. The steering system lets you turn sharply, making it easier to work in small or crowded areas.
When you use the turning brakes together with the steering, you can pivot much closer than with steering alone. This combination steering-and-brake method helps when mowing around obstacles or navigating narrow paths.
It also improves your ability to position the tractor accurately for attaching or detaching implements. The tractor can make controlled turns even at low speeds, which is important for tasks like loader work, tilling, or moving hay bales in a barn.
Having a tight turning radius reduces the number of maneuvers you need to make during fieldwork.
Service Brakes (Wet Disc, Dry Drum, etc.)
The AGCO ST33A is equipped with wet disc brakes. These brakes are fully enclosed in oil for better cooling and to protect them from dirt and moisture.
This setup reduces wear and extends the lifespan of the brakes compared to dry drum or dry disc brakes. Wet disc brakes provide strong, consistent stopping power.
They are less likely to fade during heavy use, so you can depend on them when operating on slopes or pulling loads. The braking system is split-type, allowing you to use either both wheels for straight stops or individual wheels for sharper turning.
Minimal brake adjustment is required, and routine maintenance usually only involves checking fluid levels and inspecting for leaks.
Parking Brake Type
The ST33A features a mechanical parking brake that engages the main brake system. You activate it with a hand lever near the driver’s seat.
When set, the parking brake keeps the tractor securely in place, which is important when parking on inclines or performing maintenance. The parking brake uses a positive locking mechanism that prevents accidental release.
It is easy to check and operate, even with gloves. For safety, the brake lever is clearly marked and designed to be used quickly without confusion.
You should always apply the parking brake before leaving the seat or working near implements. This added safety step helps prevent rolling, especially when the tractor is on uneven or sloped ground.
Table: AGCO ST33A Steering & Brake Specifications
| Feature | Type/Details | Key Benefits |
|---|---|---|
| Steering System | Power-assisted hydraulic | Easier, reduced-effort steering |
| Turning Radius | Tight; enhanced with turning brakes | Easier maneuvering in tight spaces |
| Service Brakes | Wet disc brakes, oil-immersed | Better stopping power; longer lifespan |
| Parking Brake | Mechanical, hand lever, positive locking | Secure parking; safer operation |
Cab & Operator Station
You will spend most of your time in the cab or operator station, so features like safety, comfort, and controls have a direct impact on productivity and fatigue. The quality of the seat, climate control options, and noise levels can make long hours much easier.
ROPS / Cab Option
The AGCO ST33A comes standard with a ROPS (Rollover Protective Structure) for safety. This is important on sloped or uneven terrain because it protects you in the event of a rollover.
The ST33A typically does not have a factory-installed enclosed cab, but aftermarket cab kits are available. You can fit canopy and enclosure options specifically made to fit the ST28A and ST33A.
These help provide some weather protection, especially useful in cold or rainy conditions. While a fully enclosed cab is not standard, adding one improves comfort and can increase the working season.
ROPS meets safety regulations and should remain upright and in good condition. Always fasten your seatbelt when using ROPS.
Look for aftermarket cabs that do not interfere with ROPS or impede visibility, and that allow for easy entrance and exit.
Climate Control (A/C, Heater, Filter)
The ST33A does not come with factory-installed air conditioning or heater, as it is delivered in an open station configuration. If you install an aftermarket cab, you can add a heater and sometimes a fan, but air conditioning is rarely available for compact tractors in this range.
Heater kits for aftermarket cabs use the engine’s coolant system to blow warm air into the cab area. This makes it more comfortable if you work in cold weather or have to plow snow.
Ventilation through windows or fans helps reduce heat in warmer months, but you will not typically have full climate control. Cab filter systems are usually not standard on this tractor, so you need to open windows for fresh air.
Be aware of dust if you work in dry or windy areas. Always check compatibility before adding any climate system to avoid damaging the original wiring or cooling systems.
Seat & Suspension
You get a basic suspension seat with the AGCO ST33A. It is adjustable to accommodate different operators.
The seat provides reasonable support and comfort for short- and medium-duration tasks, though it lacks advanced features like air suspension. You can adjust fore-aft position and backrest angle.
Some seats come with armrests, while others do not. If you plan to spend long hours in the seat or work on rough ground, consider adding an upgraded aftermarket seat with better padding and more suspension travel.
Adding a quality seat reduces back and hip fatigue, especially on uneven terrain. Always keep the seat in good condition and adjust it before starting work.
For the safest operation, ensure the seatbelt is always used and is not twisted or frayed.
Noise Level (dB A @ Operator Ear)
Noise level is an important factor for operator comfort. The AGCO ST33A’s diesel engine produces typical noise for a tractor of its size, often measured between 80 and 85 dB A at the operator’s ear during heavy use.
Open station designs expose you to engine and implement noise. Hearing protection is recommended when operating for extended periods.
Installing a cab or canopy may reduce perceived noise slightly. Only a fully enclosed, insulated cab would provide significant sound dampening.
Prolonged exposure to high sound levels can lead to hearing loss. Always check your owner’s manual for specific noise ratings and recommended protection.
Consider using over-ear hearing protection or earplugs if working for long shifts or in enclosed spaces.
| Feature | AGCO ST33A Details | User Tips/Notes |
|---|---|---|
| ROPS/Cab Option | Standard ROPS, No factory cab. Aftermarket canopy/enclosures available. | Use seatbelt; keep ROPS clear. Aftermarket cabs may improve comfort. |
| Climate Control | No factory A/C or heater. Heater/fan possible with aftermarket cabs. | Open windows for air. Heater uses engine coolant. No cab filters. |
| Seat & Suspension | Adjustable suspension seat. Basic comfort, upgradeable. | Adjust correctly for support. Upgrade if needed for longer use. |
| Noise Level (dB A) | 80-85 dB A typical at ear. Open station is noisy. | Use hearing protection. Cabs help, but only a full cab is quiet. |
Hydraulics
The AGCO ST33A is equipped with a hydraulic system that supports a range of farm and utility tasks. Key features that affect daily operation include pump type, flow rates, and valve options.
System Type (Open-Center / Closed-Center / PFC)
You get an open-center hydraulic system on the AGCO ST33A. This means fluid flows continuously through the valves and back to the reservoir when controls are not engaged.
Open-center systems are simple and reliable. They are easy to maintain, which helps reduce downtime for small tractor operators.
The straightforward design offers steady hydraulic performance for most implements. You do not need to operate complex electronic controls with this style.
The open-center setup makes it a practical choice for basic fieldwork, loader use, and light backhoe attachments.
Implement Pump Flow (L min⁻¹)
The implement pump on this model provides a flow of approximately 29 liters per minute (L/min), or about 7.7 to 8 gallons per minute (gpm). This flow rate is significant for a compact tractor of this size.
This rate is enough to power typical implements like loaders, backhoes, or hydraulic mowers. With near 30 L/min, you will see good lift and tipping speeds.
You do not usually experience delays or sluggishness with implements using this hydraulic flow.
Steering Pump Flow (If Separate)
On the AGCO ST33A, the hydraulic flow for the steering system is combined with the main implement pump. There is not a dedicated, separate pump for steering.
Combined systems are common on compact tractors. Steering performance depends on overall system demand but generally remains smooth unless multiple hydraulic functions are in use at the same time.
If high implement demand is placed on the system and steering feels heavy or slow, it is usually brief.
Total Combined Flow
The total combined hydraulic flow on the ST33A is about 7.7 to 8 gpm (29 to 30 L/min). This gives enough power to operate several hydraulic tools at once for light to medium-duty jobs.
You may experience a small reduction in performance using multiple functions at the same time, such as steering and loader use under heavy load.
System Pressure (bar / psi)
The AGCO ST33A hydraulic system operates at moderate pressure typical for compact tractors. System pressure is generally around 175 bar (2500 psi).
This pressure allows you to use heavy-duty attachments that require solid lifting force. Most common implements, such as loaders or backhoes, perform well with this pressure rating.
The pressure is maintained by a reliable pump and easy-to-service lines.
Remote Valves (Number & Type)
You may have one or two rear remote hydraulic valves on the AGCO ST33A, depending on your specific configuration. These standard spool valves support single-acting or double-acting cylinder use.
This setup lets you control external implements like rear blades, mowers, or log splitters directly from the seat. Each valve is operated by a simple lever near the operator’s area.
You can usually order a second rear remote as an option if needed.
| Hydraulic Feature | Details |
|---|---|
| System Type | Open-center |
| Implement Pump Flow | 29 L/min (7.7–8 gpm) |
| Steering Pump Flow | Shared with main pump (combined system) |
| Total Combined Flow | 29–30 L/min (7.7–8 gpm) |
| System Pressure | 175 bar (2500 psi) |
| Remote Valves | 1–2 (standard spool, single-acting or double-acting) |
Three-Point Hitch (3PH)
The AGCO ST33A tractor’s three-point hitch is important for attaching and using a wide variety of implements. Its capacity and control features affect what tools you can connect and how well they perform in the field.
| Feature | Details |
|---|---|
| Hitch Category | Category 1 |
| Lift Capacity @ Ball Ends | About 2,200 lbs (varies by spec/options) |
| Draft Control | Position control only |
| Top-Link Sensing | No |
Hitch Category (1 / 1N / 2 / 3)
The AGCO ST33A uses a Category 1 three-point hitch. This is the most common type found on compact tractors in the 30-40 horsepower class.
Category 1 hitches have lower link pins that measure 7/8 inch in diameter, and they are spaced about 26 inches apart. Category 1 hitches fit a wide selection of small to medium implements.
Most common tools—like rotary cutters, box blades, and tillers—are made to fit Category 1. You do not need special adapters or unique hardware with Category 1.
Most aftermarket and dealer-supplied implements will connect directly to the ST33A. Always check the implement manual for compatibility.
Lift Capacity @ Ball Ends
The lift capacity at the ball ends for the AGCO ST33A’s three-point hitch is about 2,200 pounds (see the owner’s manual for exact numbers, as specs can change with options and production years). This capacity decides the size and weight of the implements you can lift and use.
Lift capacity ratings are at the hitch point, not always at further distances like 24 inches behind the hitch. Heavier or longer implements may decrease what you can lift and safely transport.
A typical 33 hp compact tractor like the ST33A can operate a range of implements, including medium rotary mowers, blades, and light loaders. If your implement is too heavy, you risk damaging the hitch or reducing tractor stability.
Draft / Position Control
On the AGCO ST33A, you get position control, but not draft control. Position control lets you precisely set the height of the implement.
You move a lever to raise or lower the tool to your preferred working height. This is good for consistent depth when using tools like a blade or mower.
Draft control is not present on the ST33A. Draft control is more common on larger, higher-horsepower models.
Without draft control, you will need to manually adjust the implement if ground conditions change. For many tasks on a compact tractor, position control is enough.
Top-Link Sensing (Yes/No)
Top-link sensing is not available on the AGCO ST33A. Top-link sensing is a feature used mostly on bigger tractors with advanced draft control systems.
Since the ST33A does not use top-link sensing, you have manual control over all hitch adjustments. This is typical for compact and utility tractors in this horsepower range.
All implement adjustments—height, tilt, and angle—must be set using the standard levers and manual top-link position.
Axles & Load Limits
Understanding axle capacities and load limits helps you get the best performance and lifespan from your AGCO ST33A. The tractor’s front and rear axles, along with the final-drive setup, directly influence how much weight you can lift, tow, and carry.
| Component | Specification | Notes |
|---|---|---|
| Maximum Front-Axle Load | Not typically specified | Designed for balance; often less than rear |
| Maximum Rear-Axle Load | 2,425 lbs (1,099 kg) | Key for safe 3-point hitch operation |
| Rear Lift at 24″ | 1,610 lbs (730 kg) | How much you can safely lift at measured distance |
| Rear Axle Category | Category I | Fits most implements for this size tractor |
| Final-Drive Type | Planetary gear | Strong, durable, suitable for tough loads |
| Four-Wheel Drive Option | Yes | For increased traction and load distribution |
Maximum Front-Axle Load (kg)
The front axle on the AGCO ST33A is built to support the engine, front loader, and heavy implements. The precise weight capacity is not always published, but the main limits depend on tire choice and how the tractor is loaded.
Front axles on compact tractors like the ST33A are typically rated for less weight than the rear. This is because the main lifting and pulling force occurs at the back.
You must not overload the front axle, as doing so can cause steering and stability problems. If you use a front-end loader, adding ballast to the rear helps prevent lifting the back wheels, which will keep the front axle load within safe limits.
Always consult your owner’s manual for exact figures for implements and weights.
Maximum Rear-Axle Load (kg)
The rear axle carries most of the AGCO ST33A’s working weight. The maximum rear lift at the ends of the lower links is 2,425 lbs (1,099 kg).
At 24 inches out from the hitch points, the maximum safe lift drops to 1,610 lbs (730 kg). This matters if you use heavy implements or attachments that extend away from the tractor.
Overloading your rear axle can damage the axle or cause unsafe driving. Rear axles are designed to take high loads, but balancing the tractor and using proper ballast are important for safety and efficiency.
Final-Drive Type
The AGCO ST33A uses a planetary gear final drive system. Planetary gears are stronger than simple straight-cut gears and spread the load over multiple paths.
This makes them reliable for carrying heavy loads and for tasks that need strong torque at low speeds. The drive system is enclosed and built to require minimal maintenance under normal conditions.
Four-wheel drive is included, giving you better traction and sharing load forces between both axles. This is especially helpful in mud, fields, or slopes.
With this setup, you get strength, traction, and durability for both daily tasks and heavier work.
Proper maintenance, like checking fluid levels and inspecting seals, will keep your axles and final drive working smoothly.
Tires & Track Options
The AGCO ST33A offers different tire and track setups for a range of uses, including farming, landscaping, and construction. You can choose from various tire sizes and styles to improve grip, reduce soil compaction, or handle tough ground.
Standard Front Tire Size (Ag / Turf / Industrial)
The standard front tires for the ST33A depend on the type of work you plan on doing. For general agriculture, typical sizes include 7.00-16 Ag tires for good traction in loose soil.
Turf tires, often sized 25×8.50-14, are made to protect lawns and reduce damage to delicate surfaces. Some users prefer industrial (R4) tires, like the 27×8.50-15, for better durability on harder or mixed surfaces.
Tire treads and sizes are chosen based on your field and work needs. Ag tires have deeper lugs for muddy or uneven farmland, while turf and industrial tires are wider for stability or durability.
Standard Rear Tire Size
The rear tires do much of the work and also have size options based on use. 11.2-24 Ag tires are a common choice, giving you great grip for plowing or towing.
For turf work, you may find 355/80D-20 or similar turf tires that spread the tractor’s weight and minimize ruts. Industrial tires for the rear could be sized at 15×19.5, offering added sidewall strength and longevity on mixed terrain.
Matching your rear tires with your front tires is important for the best stability and performance.
Optional Duals / Tracks / Flotation Kits
You have options to increase flotation or traction even more. Optional duals (pairing a second set of rear tires) help in soft or wet ground, spreading weight and reducing compaction.
Rubber track conversion kits, though less common, are available for the ST33A if you need the tractor to float over muddy or sandy fields. Track kits can greatly improve performance in tricky field conditions.
Flotation kits may also be available, usually in the form of wider tires for both the front and rear. These kits are designed for areas sensitive to soil compaction, like turf farms or wet meadows.
| Option | Standard Sizes | Intended Use | Features / Benefits |
|---|---|---|---|
| Front Ag Tires | 7.00-16 | General agricultural work | Good traction, deep tread |
| Front Turf Tires | 25×8.50-14 | Lawn, turf care | Low impact, wide, gentle tread |
| Front Industrial Tires | 27×8.50-15 | Mixed/commercial use | Durable, puncture resistant |
| Rear Ag Tires | 11.2-24 | Plowing, field work | Strong grip, deep lugs |
| Rear Turf Tires | 355/80D-20 | Turf/lawn applications | Spreads weight, reduces ruts |
| Rear Industrial Tires | 15×19.5 | Heavy duty/mixed terrain | Stable, strong sidewalls |
| Optional Duals | – | Wet/soft ground | Reduces compaction, better grip |
| Track Conversion Kits | – | Extreme mud, sand | Improved flotation, less sinking |
| Flotation Tire Kits | Wide turf/ag sizes | Sensitive soils, wet fields | Low compaction, wide footprint |
Dimensions & Weight
When looking at the AGCO ST33A Tractor, its size and weight matter for transportation, storage, and field performance. You will find details about the tractor’s wheelbase, length, width, height, ground clearance, and weights to guide your buying or operational decisions.
| Specification | Measurement |
|---|---|
| Wheelbase | 65.5 inches (166 cm) |
| Overall Length | 114.6 inches (291 cm) |
| Overall Width (Minimum Tread) | 49.6 inches (125 cm) |
| Height To ROPS / Cab | 79.1 inches (200 cm) |
| Ground Clearance | Not specified (est. ~13-15 in) |
| Shipping Weight | 2205 lbs (1000 kg) |
| Operating Weight (With Fluids) | 2474 lbs (1123 kg) |
Wheelbase
The wheelbase of the AGCO ST33A Tractor measures 65.5 inches or 166 centimeters. This is the distance between the front and rear axles.
A moderate wheelbase balance helps your tractor maintain stability, especially over uneven ground and during turns. A 65.5-inch wheelbase strikes a middle ground, making it easy to maneuver in tight spaces like barns or around buildings.
This measurement is also important for weight distribution. A properly balanced wheelbase reduces the risk of tipping, especially if you are driving on slopes or carrying heavy rear implements.
The stable wheelbase of this tractor helps with smoother rides and more precise steering. For most operators, this length allows for both adequate field coverage and the ability to transport or store the unit without needing oversized transport equipment.
Overall Length
The overall length of the AGCO ST33A is 114.6 inches (291 centimeters). This refers to the measurement from the front to the furthest point at the rear, not including attachments.
The length impacts how the tractor fits in storage areas, sheds, and on transport trailers. This size gives you a machine that is easy to handle in most farm environments.
Parking the tractor is simple and loading it onto standard trailers is possible without special equipment. The length also plays a role in how much space you need for turning and maneuvering at the ends of rows or in confined barnyards.
If you add front or rear attachments, such as loaders or backhoes, the length will increase. For most routine uses, the factory length keeps the machine compact and practical for general agricultural, mowing, or landscaping jobs.
Overall Width (Minimum Tread)
The minimum tread width, or overall width, is 49.6 inches (125 centimeters) on the AGCO ST33A tractor. This dimension allows you to use the tractor in narrow spaces.
It helps when working between crop rows or navigating close to fences, walls, or other barriers. A width under 50 inches means you can get through standard-sized gates easily.
It also allows for more storage options in sheds or garages. The narrow tread helps reduce soil compaction on the field since less area is making contact with the ground.
You should be aware that adjusting the tread width may be possible on some models by changing the wheel setup. If your applications call for wider stability or different implement requirements, check your tractor’s manual for options.
Most operators find the factory width suitable for general applications such as mowing, tilling, and transportation.
Height To ROPS / Cab
The AGCO ST33A’s height to the top of the ROPS (Roll-Over Protective Structure) or cab is 79.1 inches (200 centimeters). ROPS is required for operator safety and is included on most modern tractors.
This height affects your ability to enter low-clearance barns, garages, or other covered areas. A height of about 6.6 feet allows access to many farm buildings with standard overhead clearance.
You can drive under most garage doors and through equipment sheds without lowering or removing the ROPS. Having this height keeps you safe while operating yet does not make the tractor overly tall or unstable.
If your tractor has no cab and only the ROPS, the height will be less than with an enclosed cab. You should measure your access points to avoid damage to the ROPS or building.
Most users will find the tractor’s design allows for flexibility in a range of storage and field settings.
Ground Clearance
Exact ground clearance for the AGCO ST33A is not specified in the available documentation, but similar compact tractors of this class offer about 13 to 15 inches (33 to 38 centimeters) of clearance. Ground clearance is the distance from the ground up to the lowest point of the frame or axle.
Adequate ground clearance helps you avoid getting stuck on rough terrain and prevents damage to undercarriage components. This is especially important if you are working on uneven or muddy fields, crossing shallow ditches, or handling rough tracks.
You have enough clearance to work in most field conditions common to compact utility tractors. It also makes driving over crop residues, small stumps, or debris less risky.
If you expect to use your tractor in areas with very rough ground, verify the actual measurement by checking under your unit.
Shipping Weight
The shipping weight of the AGCO ST33A is 2205 pounds (1000 kilograms). Shipping weight means the mass of the tractor as delivered from the factory, without extra attachments, fluids, or fuel.
It is important to know for trailer loading, freight quotes, and rigging requirements. If you are moving the tractor between locations, the shipping weight lets you choose the right trailer or flatbed.
Ensure the transport vehicle or trailer has a weight capacity that safely exceeds your tractor’s shipping weight. Also, allow for any extras you might add, such as a loader or weights.
For lifting, securing, or handling during shipment, use the shipping weight as your base estimate. It’s a compact tractor, so you can use most medium-duty trailers and ramps for transport needs.
Always refer to your operator’s manual for tie-down and transport best practices.
Operating Weight (With Fluids)
The operating weight of the AGCO ST33A tractor, including fluids such as oil, coolant, and a full fuel tank, rises to about 2474 pounds (1123 kilograms). Operating weight also assumes the tractor is ready to work but does not include optional attachments or ballast.
You must consider operating weight for field performance, tire selection, and transport safety. This extra weight improves traction and stability on soft ground or slopes.
When towing or carrying loads, your tractor will perform as expected under most conditions because of its proper weight balance. If you plan to use implements or add counterweights, factor in these extras when calculating your total weight for transport or fieldwork.
Knowing the difference between shipping and operating weight ensures you are prepared for both safe operation and legal road transport.
Fuel & Fluids
To keep your AGCO ST33A Tractor running smoothly and efficiently, you need to know the right types and amounts of fuel, engine oil, and hydraulic fluid. Keeping proper levels of these fluids is essential for engine health, hydraulic performance, and smooth operation.
Fuel-Tank Capacity
The AGCO ST33A uses standard diesel fuel and does not require gasoline or alternative fuels. The fuel tank on this model holds 7.1 gallons (27 liters) of diesel.
This amount is suitable for most daily tasks, letting you complete long hours of fieldwork or mowing without frequent refueling. To fill the tank, always shut off the engine and allow it to cool.
Use clean, fresh diesel, and avoid storing fuel in open containers as this can lead to contamination. A tight-fitting fuel cap reduces the risk of spills or evaporation, helping to maintain the quality of your diesel.
Checking your fuel level regularly ensures you won’t run out during operation. Keeping your tank at least half full helps prevent condensation, especially in humid or cold environments.
DEF-Tank Capacity (If Applicable)
The AGCO ST33A tractor does not require a Diesel Exhaust Fluid (DEF) tank. This compact tractor model was produced before DEF systems were common on equipment of its size and class.
This means you won’t need to worry about refilling or maintaining a DEF tank. You also avoid the risk of mixing up fluids or running into DEF shortages during important projects.
Just focus on routine diesel refueling instead. Always check your operator’s manual for updates in case emission rules change in your area or you have a later model.
Engine Oil Capacity
The engine oil capacity for your AGCO ST33A is 4.2 quarts (4.0 liters), including the filter. Change the engine oil at least every 100 hours of use or once per season, whichever comes first.
Always use high-quality oil rated for diesel engines in tractors. Check the oil level before each use, and top off if needed.
Running the engine with too little oil can cause rapid wear or engine damage. Use the dipstick to check the level, making sure the tractor is on a level surface.
Engine oil should appear clean, without debris or a burned smell. When changing oil, replace the filter each time.
Dispose of old oil and filters safely according to local laws.
Hydraulic/Transmission Oil Capacity
The ST33A has a shared hydraulic and transmission oil system, which holds approximately 6.3 gallons (24 liters). It is important to keep the oil at the correct level to ensure smooth shifting, efficient lift operations, and proper steering function.
Use only the manufacturer-recommended hydraulic/transmission oil. Never mix brands or types, as this can cause system problems.
Change the hydraulic/transmission oil based on the hours listed in your manual, usually every 300-400 hours. Leaks or cloudy oil can signal problems.
Watch for any drops in the oil level and fix leaks right away. Dirty or foamy oil should be replaced as soon as possible to avoid damaging internal parts and to keep your implements running smoothly.
| Fluid/System | Capacity | Type Required | Maintenance Interval | Notes |
|---|---|---|---|---|
| Fuel Tank | 7.1 gal (27 L) | Diesel | As needed | Keep tank clean, avoid water |
| DEF (if applicable) | Not required | N/A | N/A | No DEF tank on this model |
| Engine Oil | 4.2 qt (4.0 L) | Diesel engine oil | Every 100 hours or yearly | Change oil filter with oil |
| Hydraulic/Trans Oil | 6.3 gal (24 L) | Manufacturer recommended oil | Every 300–400 hours | Shared hydraulic/transmission |
Electrical System
The AGCO ST33A tractor uses a straightforward 12-volt electrical system. This system powers the lights, starter, gauges, and charging circuit, making sure you get reliable performance when operating or maintaining the tractor.
Ground Type (Negative / Positive)
The AGCO ST33A tractor uses a negative ground electrical system. This is a common design in most modern tractors and vehicles.
In a negative ground system, the negative terminal of the battery is connected directly to the tractor’s frame and chassis. This setup improves electrical reliability and reduces corrosion in the wiring connections.
Using a negative ground allows for easier troubleshooting if you have issues with shorts, blown fuses, or malfunctioning electrical equipment. You can safely connect standard electrical testers and equipment, since most automotive tools are designed for negative ground systems.
Keep battery terminals and the ground strap clean and tight. This helps prevent voltage drops and starting problems, which can happen if corrosion builds up where the system grounds to the chassis.
Alternator / Charging System
The AGCO ST33A comes equipped with an alternator-based charging system. The alternator is driven by the tractor’s engine, providing electrical current to recharge the battery and run all the electric systems while the engine is operating.
Unlike older generators, alternators give you better charging at lower engine speeds and are more reliable in modern compact tractors like the ST33A. The alternator ensures that the lights, starter, gauges, and accessories receive steady electrical power as you work.
Routine checks of the alternator belt are important. A loose or worn belt can reduce charging and drain the battery.
If you notice dim lights, slow cranking, or a dashboard warning, inspect the alternator system and wiring as part of your regular service routine.
Charging Output (Amps)
The charging system on the AGCO ST33A typically provides an output in the range of 35 to 40 amps. This is enough power to handle the tractor’s electrical needs, including starting, lighting, and running any electronic accessories.
A charging output in this range gives you enough capacity even if you use extra work lights or a 12-volt sprayer. For reference, most tractors in the 30–40 horsepower class use alternators in this amperage range.
Check your owner’s manual or the tag on the alternator for the exact output rating. If you add high-demand electrical accessories, make sure the alternator’s output is sufficient to avoid overtaxing the system.
Battery Voltage
The AGCO ST33A runs on a 12-volt electrical system. This is standard for compact tractors and matches the requirement for most agricultural and automotive batteries and accessories.
The 12-volt battery powers key systems like the starter and ignition. It also provides power to all the lights, dashboard, and safety features.
You can use a standard 12-volt charger or maintainer to keep the battery in good shape during long storage periods. Always disconnect the 12-volt battery when doing any electrical repairs.
Use a voltmeter to check the battery if you have starting or charging issues—below 12 volts on a standing battery means it should be recharged or replaced.
Battery CCA Rating
The recommended battery for the AGCO ST33A has a Cold Cranking Amps (CCA) rating of 600–800 CCA. CCA is a key measure of a battery’s ability to provide enough power for the starter during cold weather.
A higher CCA rating means your tractor will start more reliably in winter or if your engine is slow to turn over. Using a battery with at least the minimum recommended CCA protects your starter motor and wiring from damage caused by low voltage.
Always replace your battery with one that meets or exceeds the recommended CCA. Clean and tight terminals, along with good CCA, help your tractor start quickly and prevent electrical problems year-round.
AGCO ST33A Electrical System Overview
| Feature | Details |
|---|---|
| Ground Type | Negative ground (chassis-grounded) |
| Alternator Type | Engine-driven alternator |
| Charging Output | 35–40 amps (typical) |
| Battery Voltage | 12 volts |
| Battery CCA Rating | 600–800 CCA recommended |
| Key Electrical Components | Starter, lights, gauges, ignition, wiring |
| Maintenance Notes | Check belts, clean terminals, verify output |
Total Cost Of Ownership Metrics
The AGCO ST33A Tractor 33 hp requires scheduled service, ongoing maintenance, and fuel, which all add up over time. Knowing what to expect in terms of costs and usage helps plan for your yearly budget and long-term value.
Recommended Service Intervals
You should follow the manufacturer’s recommended service intervals to keep your ST33A tractor in good working condition. Routine tasks like oil changes, fuel filter replacements, and air filter checks are typically required every 100-200 hours of operation.
Major services, such as transmission and hydraulic fluid changes, are usually scheduled at 400-600 hour intervals. If you operate your tractor in dusty or tough environments, you may need to service some parts more often.
Always check the owner’s manual for the exact schedule.
Estimated Annual Maintenance Cost
The annual maintenance cost for your AGCO ST33A includes routine service, parts, and labor. On average, you can expect to spend between $600 and $1,000 each year with moderate use.
Costs may be higher if you use your tractor heavily or need to replace major components like tires or batteries. Preventative maintenance, like frequent oil and filter changes, can help reduce unexpected expenses.
Labor rates and parts prices vary by region. Doing some maintenance yourself, such as oil and filter changes, can help lower your overall costs.
Budgeting for yearly maintenance helps you avoid surprises.
Depreciation Curve (% Per Year)
Tractor depreciation is usually highest in the first few years of ownership. For the AGCO ST33A, you can expect it to lose about 10% to 15% of its value in the first year.
Over the next 4-5 years, the depreciation rate typically drops to around 6% to 9% per year. Factors like hours of use, condition, and maintenance history affect resale value.
After 7-10 years, your tractor will have lost most of its original value, but well-maintained models still hold some resale worth.
| Year of Ownership | Depreciation (%) | Retained Value (%) |
|---|---|---|
| 1 | 10-15 | 85-90 |
| 2-5 | 6-9 (each year) | 55-75 |
| 6-10 | 3-5 (each year) | 35-50 |
Fuel Consumption @ Rated Load (L hr⁻¹)
At rated load, the AGCO ST33A with its 33 hp engine typically consumes about 3.5 to 4.2 liters of diesel fuel per hour. Actual consumption varies based on factors like soil conditions, task difficulty, downtime, and engine condition.
Lighter workloads use less fuel, while heavy tasks like tilling or mowing use more. Clean filters, correct tire inflation, and proper driving habits can help reduce your average fuel use.
| Operating Condition | Fuel Consumption (L/hr) |
|---|---|
| Light Load | 2.2 – 3.2 |
| Rated Load | 3.5 – 4.2 |
| Heavy Load | 4.5 – 5.0+ |