Review and technical characteristics of the Vladimirets T-25 tractor

The T 25 wheeled tractor is a favorite of domestic farmers and has a history of almost half a century, since the first copy of this machine came out of the gates of the Kharkov Tractor Plant back in 1966.

The new 0.6 t class machine was intended to perform a wide range of work in small field areas. Until now, various modifications of this tractor regularly serve on collective farms and farms for sowing, processing and subsequent care of vegetables.

Museum "Vladimirets"

In Kharkov, the T 25 tractor was not produced for long - until 1972. In the same year, production was established at the Vladimir Tractor Plant. Distinctive features of this machine are the ability to adjust the track and ground clearance, as well as the longitudinal base. So, if the latter decreased, then the maneuverability of the vehicle increased.

With an increase in the base, the longitudinal stability of the tractor sharply increased, which allowed it to work with fairly heavy attachments. Another feature that the Vladimirovets T-25 tractor had was the ability to reconfigure it to operate in reverse.

Specifications

“Vladimirets” belongs to the 0.6 traction class equipment. Today farmers use three modifications of the T-25:

• T-25A, which has all-wheel drive and is equipped with a reinforced cabin;
• T-25A2, devoid of a cabin and having only an awning over its head;
• T-25A3, which received only a safety cage.

The technical characteristics of the T-25 tractor are the same for all its variants.

The dimensions of the T-25 tractor may vary depending on the configuration. For example, when installing 9.5/32” tires, the length of the machine with a hydraulic mounted system will be 3110 mm, and with 10/28” tires – 3098 mm. With the same configuration, the width of the tractor will be 1370/1467 mm, and the height will be 2500/2488 mm, respectively.

The agricultural clearance, which is measured under the brake hoses, also depends on the tire size.

The mass of the car also changes. With 9.5/32” tires, the design weight of the T-25 model will be 1780+50 kg, with 10/28” – 1820+50 kg. Operating weight – 2022 and 2060 kg, respectively.

Technical characteristics of T-25A

The characteristics of the T-25A tractor allow the machine to be used for pre-sowing tillage, planting crops, hay harvesting, processing vegetable crops and gardens, transportation, etc. The tractor can act as a drive for stationary machines. The model belongs to the 0.6 traction class and has a semi-frame design.

The T-25A tractor is equipped with an 8-speed manual reversible gearbox and a dry, permanently closed single-plate clutch. The rear drive axle is equipped with a bevel differential with forced locking and a dependent PTO. There is no front axle differential. The brake system is separate dry band. The T-25A model has mechanical steering without power steering. The pressure in the hydraulic system reaches 12 MPa (a gear pump with a capacity of 15.7 l/min is installed).

Photo source: techstory.ru Photo of the T-25A tractor

Basic model and modifications

The prototype of the T28 was the DT24. The new Vladimirets was equipped with a more powerful and, at the same time, more economical engine, the weight was reduced and the design was simplified.

The popularity of the light universal tractor T28 in farms and private households is evidenced by the fact that it is still actively sold and bought on the secondary market.

The basic version of the Vladimirets T28 was produced at the development plant for six years, until 1964.

The Vladimirets T28X modification, intended for processing cotton fields, was produced in Tashkent until 1970, and the improved models T28X2 and T28X4 until 1995.

Main technical characteristics of the basic model T28:

Modifications and their differences from the base model:

It is possible to change the track width within the range of 1.80 - 2.40 m.

When working on muddy ground, the tractor can be converted into a half-track. It is possible to replace the drive wheels with rubberized belts with lugs.

Diagram of the position of the gear selector levers in the cabin of the T28x4m tractor. The gearbox ensures reliable shifting and also blocks the tractor from starting when any gear is engaged. The manufacturer recommends switching with a pause in the “neutral” position.

Models and modifications

The T-25 tractor was produced in two varieties, which differed in the size of the rear wheel tires installed: T-25 C1 had rear wheel tires measuring 9-32″, T-25 C2 had rear tires measuring 10-28″. Depending on the nature of the work, each of these two models can be converted into one of the following modifications.

In the low version, the tractor works in gardens and forest areas. In this case, the final drive is installed horizontally: the drive wheels are turned forward along the tractor, and the axles of the front wheels are moved to the upper position. In this modification, the longitudinal base of the tractor is 1423 mm, and the ground clearance is 308 mm. If it is necessary to increase the stability of the tractor unit, the final drive can be moved backward along the tractor. In this case, the longitudinal base will be equal to 1837 mm.

The high modification is intended for inter-row cultivation of garden crops. In this modification, the final drive is mounted vertically, with the large gear wheel down, and the front wheel axles are set in the lower position. The longitudinal wheelbase in this modification is 1630 mm, and the ground clearance is 575 mm.

In the semi-garden, or garden low, modification, the final drive is mounted at an angle of 45° to the drive wheels, back along the tractor, and the front wheels are installed in an intermediate position. At the same time, the tractor has a longitudinal base of 1775 mm, and ground clearance - 455 mm. Tractors leave the factory in this modification, which is considered the main (basic).

In some cases, when good visibility is required, the tractor can be converted to operate in reverse. To do this, the seat is moved to the opposite side and installed on the back of the hood, the steering wheel is moved to the front inclined tail, the tires of the drive wheels are placed in a position in which the arrows located on them would correspond to the direction of movement of the tractor. The track of the front wheels is changed by moving the steering knuckle housings of the wheels apart by the required amount. The tie rod is moved apart accordingly. The track of the rear wheels is adjusted by moving the discs and wheel rims to different positions.

Important TOP 4 fastest American all-terrain vehicles

On the basis of the T-25 tractor, the T-25K high-clearance tractor was created, intended for inter-row cultivation of tall crops. It has a ground clearance of 1500 mm and a track of 2800 mm. The machine is raised above the ground level on the front and rear wheel stands. The rear wheels are driven by chains located in the racks.

Such a machine can be obtained directly on the farm from a conventional T-25 tractor by converting it with the installation of additional components: elongated rear wheel sleeves, front and rear wheel struts, front balancer. After completing work on processing tall crops, the special equipment can be removed and the tractor can be used in its usual form.

In the process of improving the design, the T-30A80 model was developed, which differs from its predecessor in the engine (D-120), all-wheel drive, hydrostatic steering, and a more comfortable cabin.

Technical characteristics of the T-4A tractor

Despite the early years of design and the start of production, the T-4A tractor is a real hero in its class. Its technical characteristics are truly outstanding. Even in comparison with modern analogues existing today, it continues to look quite impressive.

Dimensional and mass indicators

Let's consider the mass and dimensional indicators of this equipment - this will allow us to imagine it in operation and evaluate its ease of use in various conditions:

• fuel tank volume, l – 320;
• width of the created track, mm – 1384;
• longitudinal base length, mm – 2,522;
• ground clearance, mm – 340;
• width of the shoes used in the design, mm – 420;
• the value of pressure on the soil, MPa – 0.04.

Overall dimensions of the body itself:

• length from the rear of the tracks to the front edge of the body, mm – 4,684;
• width from the edges of the tracks, mm – 1,952;
• height from the bottom of the tracks to the top of the cabin, mm – 2,545.

The structural weight with all filling fluids is 8,145 kg. Many people consider the tractor to be clumsy due to its heavy weight. But thanks to its powerful engine, it can easily cope with its work even on the hardest soils! The T-4A tractor will prove to be a real hard worker in any conditions.

Engine

The tractor used a real giant compared to other engines - the A-01 diesel engine. Its performance parameters are truly outstanding even today, decades after its launch.

There are three different modifications of the motor. All of them were used in the T-4A tractor at various periods of time:

• A-01MSI-1;
• A-01MRSI-1;
• A-01MKSI-1.

Their performance characteristics, despite different markings, are similar to those of their siblings:

• motor type – four-stroke;
• total number of cylinders, pcs. – 6;
• cylinder arrangement – ​​vertical/in a row;
• The cylinders operate in the following order: 1/5/3/6/2/4;
• cylinder diameter, mm – 130;
• piston stroke, mm – 140;
• rated power value, hp – 135;
• rated crankshaft rotation speed, min-1 – 1,700.

Transmission

The “strong” part of the tractor is its box. It is a manual transmission, which is equipped with a reverse gearbox. There are 4 speeds for reverse and 8 speeds for forward movement. In fact, this box is similar to that used on its predecessor, the T-4 tractor. It hasn't been modified.

Chassis (transmission)

The chassis, like the gearbox, was completely inherited from its predecessor. Its main components are:

• two special track chains;
• special balancing spring – stabilizes the tractor on steep slopes and prevents it from overturning;
• two caterpillar carts.

Cabin and tractor controls

Initially, the tractor cabin was made of metal and was insulated to a minimum. Subsequently, many modernizations were carried out. All this together made it possible to achieve more or less acceptable working conditions for the driver. Although it was far from comfortable. The T-4A tractor is a machine for real men! The cab is heated and has a fan/dust separator. There is a passenger seat.

The machine was controlled using several levers for various purposes. Gear shifting was carried out using a dry clutch - it was activated by a special pedal. All sensors located on the dashboard were used only of the analog type - even on models produced in the last years of ATZ's existence.

Correct operation of the tractor is the key to savings

So, it is necessary to check the tire pressure before starting work every shift. For the front wheels it should be 1.5-1.8 atm, for the rear wheels – 0.8-0.9 atm. Moreover, these figures are given based on the fact that the machine will be used for agricultural work. In the case of transport work, the tires on the tractor should be under a pressure of 1.8-2.0 atm for the front wheels and 0.9-1.1 atm for the rear.

It is not recommended to work on tires whose air pressure exceeds the established values, since in this case the adhesion of the tread to the soil deteriorates, as a result of which the rear drive wheels begin to slip, which leads to premature tire wear. It is extremely interesting that despite its advanced age, the T-25 tractor receives mostly positive reviews.

This is due to the unpretentiousness of this machine and its fairly low cost. Therefore, many experienced farmers advise those who are just about to purchase a tractor to buy the T-25, since it is cheap, simple and does not require particularly careful maintenance.

Price of tractor T-25A

Price

What makes the T-25A tractor very competitive on the market is its price. It is an order of magnitude cheaper than other models with similar characteristics. The price and wide capabilities of the model give it an advantage over its competitors in this class of specialized equipment.

The price of the T-25A tractor fully corresponds to its quality. The price mainly depends on several factors. Before choosing, you need to decide on the model, and before that you need to clearly understand for what purposes you will use this technique. You should also decide what additional equipment will be installed in the future.

Important Review of the best Hitachi excavators

The average market price of used tractors fluctuates around 60,000-300,000 rubles. It all depends on the year of release of the equipment, modifications and availability of additions.

Dimensions of T-25A

Photo source: techstory.ru The power of the T-25A tractor is 21 kW

Technical characteristics of the T-25A tractor:

T-25A is a wheeled, universal tractor.

• Engine make – D21A1
• Towing class - 0.6 t.
• Engine power (Diesel) – 19.5 (26.6) kW (hp)
• Number of forward/reverse gears – 8/6
• Tractor dimensions length/width/height mm. – 3180/1472/2477
• Track - 1200–1400 mm.
• Weight - 2022 kg.
• Maximum speed – 21 km/h.
• Fuel consumption g/kW*h – 223
• Load capacity – 600 kg.
• Power take-off shaft rpm. – 540

Tractor engine T-25

Reliable, time-tested, four-stroke power plant, air-cooled. The model range was developed at the Vladimir Tractor Plant. There are 2, 4, 6, cylinder models, with many unified parts. The T-25 is equipped with a two-cylinder model D21A1 with a power of 19.5 kW (26 hp).

The engine is famous for its unpretentiousness to fuels and lubricants, maintainability and simplicity of design. Also, the design features include a dual (pressure and splash) lubrication system.

On a warm engine, the oil pressure should be 1.5–3.5 kgf/cm² at nominal speed. Long-term idling of the engine is not recommended.

The unit is mounted on three supports. The two front ones are elastic, rigidly attached to the engine, located on a semi-frame, on rubber cushions. The rear part of the engine is rigidly attached to the connecting body of the tractor by the flywheel housing flange.

Gearbox of the T-25 tractor

The Vladimirets tractor is equipped with a mechanical transmission. The gearbox is equipped with reverse and doubler, thanks to which the machine has a wide range of speeds, 8 forward/6 reverse. This set of gears allows the tractor to move and perform various tasks at speeds from 1.5 to 21 km/h. The clutch is dry, single-plate, permanently closed. The shafts are arranged transversely.

All gearbox mechanisms are housed in a cast housing. In the front part of the housing, on two ball bearings, there is a primary shaft, made together with a bevel gear. This gear is constantly in mesh with the bevel driven gears of the reverse mechanism, and the mechanism itself is located in the middle part of the intermediate shaft.

On the intermediate shaft to the right of the reverse mechanism, there is a movable 2/4 gear. On the left on the same shaft is a movable double gear for 1/3 and 5/6 gears.

Under the main and intermediate shafts, in the lower part of the housing, there is a drive for the rear power take-off shaft and a low gear unit.

A locking device is installed on the transmission cover; its purpose is to prevent gear shifting when the clutch is not fully engaged or disengaged. The device also protects gears from premature wear and tooth breakage.

The rear linkage mechanism, brake hoses and tractor steering elements are attached to the gearbox housing.

Dimensions and weight

Since the tractor was developed mainly for work in small, often limited areas, it received good maneuverability and compact dimensions. However, its weight of 2050 kg allows it to work quite successfully with a plow and inter-row cultivation of row crops.

Dimensions:

• Length 3180 mm.
• Width 1482 mm.
• Height 2477 mm.
• Track 1200–1400 mm.

The agrotechnical clearance is adjustable and amounts to:

• Overlay Tires 9–32” mm.
• high – 657
• main - 587
• low - 450

• Overlay Tires 10–28” mm.
• high – 642
• main - 572
• low - 435

Further development of the tractor

The following year, 1973, the Vladimir Tractor Plant launched production of a new modification of this agricultural machine under the symbol 25A, which differed from the previous one in the presence of a cabin and slightly increased engine power. In terms of the number of cars produced, the model with the “A” index was a real record holder: over the years of production, a total of 731,700 units were produced against 99,000 cars of the previous modification.

The subsequent modification with the index “A3” was the final one for the tractor model we are describing. Its distinctive feature was the appearance of a safety cage, so VTZ made only a small technical tuning of the T-25 tractor.

Although the “Vladimirets” today can be called an outdated machine, which is being replaced by new models, including its direct descendants, produced by the same VTZ, however, in the endless fields and expanses of our country, this equipment is found everywhere. That is why the question of where to get tires for the T-25 tractor is more than relevant, although they are sold by many domestic stores. However, even despite the widespread availability of rubber for this type of tractor, let us remind you that following a few simple rules will allow you to significantly extend their life.

Injection pump repair

The maximum idle speed of a diesel engine can be adjusted by changing the spring stiffness level by changing the number of its working turns.

High pressure fuel pump repair:

1. Install the fuel injection pump on the stand and connect the fuel wire.
2. Adjust the starting fuel supply by 50-100%.
3. Unscrew the screw and set the control lever to the extreme position for maximum speed.
4. Tighten the corrector screw until it stops.
5. Set the required fuel supply at the rated camshaft speed by moving the housing relative to the cover.
6. Adjust the start of fan operation to 10-15 rpm.
7. Check the fuel supply at nominal mode.
8. Test the complete shutdown of the fuel supply through the injectors.
9. Adjust the pump camshaft speed.
10. Unscrew the adjuster screw and adjust the fuel supply in accordance with the required engine torque reserve.

Power

The VTZ T-25A row-crop tractor is equipped with a four-stroke D-21A1 diesel engine with direct fuel injection. The power unit was produced at the Vladimir Tractor Plant. The motor power is 28.5 hp, or 21 kW. It is started by an electric starter. The lubrication system is combined, cooling is forced air. The internal combustion engine is equipped with a single-plunger fuel pump ND-21/2.

Main components and assemblies of the machine

Power point

Diesel engine with four working strokes, two-cylinder D-21, air-cooled and a pair of vertically arranged cylinders.

A naturally aspirated diesel engine is equipped with:

• direct fuel injection unit with a single plunger pump;
• device for mechanical all-mode speed control;
• closed-type pinless nozzles;
• a three-stage air cleaner, through which air passes before being supplied to the cylinders;
• a combined lubrication system - oil, passing through a gear pump, is supplied to the parts under pressure and sprayed;
• a settling filter for coarse purification of the oil mixture, the oil is further purified with replaceable paper filter elements in the fine filter housing;
• forced air cooling system with an axial fan on the generator shaft;
• a starting device consisting of a 12 V electric starter, a decompression mechanism and a glow plug;
• muffler with spark extinguishing function.

Important Design and principle of operation of the KamAZ engine pre-heater (PZH): how to use, error codes

Power transmission

The single-plate dry clutch mechanism is constantly closed; the mechanism is turned off using a foot pedal through a mechanical drive.

The housing with a single transmission housing contains:

• gearboxes and reverse;
• cross-wheel bevel differential assembly with satellites;
• main transmission mechanisms.

The gearbox provides 6 reversible torque transmission modes for driving the car at a speed of 5.4 to 20.5 km/h. The doubler allows the use of 2 retarding gears at speeds of 1.66 and 2.45 km/h. Modes are switched by levers with a rocker mechanism.

The onboard brake units are attached to the transmission housing perpendicular to the machine axis, on which the final drives are mounted - gear units in a single-stage design.

Power take-off for additional equipment is provided through a shaft with a dependent drive and a drive pulley of the gearbox shaft shank, both mechanisms are mounted at the rear of the tractor.

Propulsion system

Movement and direction selection are provided by the front axle and driving rear pneumatic wheels with tire sizes 9-32 or 10-28.

Front axle wheels of size 5.5-16 are steerable. It is possible to change the track of the unit from 1.1 to 1.5 m in increments of 5 cm. The ground clearance changes from 0.308 to 0.515 m.

The tubular axle of the front axle is secured by a bracket to the axle of the half-frame and allows vertical and horizontal movement.

The machine is controlled mechanically through a steering mechanism. The steering column is inclined. The unit consists of a steering wheel, a control column, a screw shaft (worm), and bevel-type gears.

The turning force is transmitted through the shaft to the worm pair, the bipod shaft, the bipod, and the lower part of the rotary rod. Through the steering linkage units, the steering wheels are affected.

Hydraulic system components

The system is unified for tractors produced in Vladimirov and allows the tractor driver, without an assistant, to connect the machine with the drawbar of trailing devices and mechanisms, and control the hydraulic actuators.

The gear-type pumping unit is unregulated; the shaft receives rotation from the diesel flywheel. It is activated by a manual handle acting on a ball clutch.

Fluid flow control by two spool valves with settings: neutral, rise, descent, floating.

Hydraulic lifting mechanism of attachments

The following are mounted on a metal frame: a hydraulic system filter, a lifting mechanism, a double-acting hydraulic power cylinder and a traction joint attachment unit.

The single-seat, two-door cabin is equipped with ventilation and heating systems. Sufficient glass area and installed lighting devices allow the tractor driver to visually monitor the work area.

Unit motor design

The design of the machine is based on a time-tested, reliable four-stroke engine, working together with an air cooling system and a gear starter. A family of motors specifically for the tractor was developed at the Vladimir plant. The model range includes 2-, 4- and 6-cylinder engines, equipped with a large number of standardized elements. As standard, the T-25 is equipped with a two-cylinder D21A1 engine with a rated power of 27 hp. With. The power of this engine model may vary slightly depending on the generator connection diagram. Provided the fuel pump is adjusted correctly, the engine will consume a minimum amount of fuel and lubricants. The design of the engine is simple and easy to repair yourself. One of the main features of the engine is the presence of a dual lubrication system that operates under splash and pressure. Thanks to the presence of this unit, the T-25 and its modification, the T25 100, is a universal tractor that can withstand operation at any time of the year and under any working conditions.

With a warm engine and a working battery with a continuous color electrical circuit, the oil pressure at nominal speed is about 3 kgf/cm2. The t25 tractor cannot be left idling for a long time.

The motor device is secured using three supports. Elastic front supports are located on the semi-frame on special rubber pads and securely hold the motor through a rigid connection. The rear part of the engine is fixed to the tractor connecting body by means of a crankcase flange.

Reliability of motor fixation significantly expands the tractor's capabilities. It can be confidently used with a bucket - in this case, the engine will not tear off one of the semi-frames, as often happens with tractors of other brands. Both as a cultivator and as a loader, the unit will show high efficiency and endurance, and its elements will be securely held in the structure. Even if some parts do fail, they can always be quickly replaced with homemade ones - this will have virtually no effect on the operation of the machine.