The importance of adjusting and maintaining agricultural tractors

By Eder Pinheiro, Massey Ferguson Tractors Product Marketing Coordinator; Saulo Ginak, Product Marketing Coordinator at Massey Ferguson; Kazuo Nunes, Tractor Marketing Specialist at Massey Ferguson; Juan Paulo Barbieri, technical consultant at Base Assessoria Agronomica; and Gustavo Oliveira dos Santos; technical consultant at Base Assessoria Agronomica

Over the years, the concept of tractor driver was replaced by machine operator, assigning this professional, in addition to the function of moving equipment, to do so correctly, consciously, safely and in accordance with a pre-established schedule. Correct preparation and maintenance of an agricultural tractor are simple operations, but necessary to preserve the machine and extend its useful life.

Maintenance can be divided into corrective or preventive. In corrective, the replacement of parts takes place after the breakage. Preventative measures follow a schedule pre-established by the manufacturer and stated in the operator's manual, which must always be at hand, and can be daily (10h), weekly (50h), monthly (200h), semi-annual (500h) or annual ( 1.000h). This procedure is divided into lubrication, adjustments, changing parts and fluids, protection against harmful agents.

To increase the engine's useful life, check the oil level daily and correct it when necessary, using the same product and according to the factory recommendation. Some brands already indicate the number of hours until the next maintenance on the instrument panel.

New tractors incorporate new technologies, and the systems' working temperature is very important for maximum efficiency. The number of radiators and engine power varies, but in general, cooling system maintenance is simple and applies to everyone in the same way. External cleaning is very important, as the accumulation of impurities in the radiator honeycombs and fins makes air circulation difficult and can cause overheating in the engine and other systems. Interlocked engines also have a radiator to cool the propellant intake air. To maintain a constant diesel temperature, some manufacturers use a radiator to return the fuel to the tank, this increases the system's efficiency. In cab tractors, there is the air conditioning condenser, which must be cleaned with compressed air or water jets in the opposite direction to the air flow. Observe the coolant level and top up when necessary.

It is necessary to drain the water and impurities from the fuel system daily, and replace the filter, observing its situation and following the manufacturer's recommendation table, so that the engine does not lose power and consume more fuel. At the end of the working day, top up to avoid moisture condensation inside the tank at night due to the drop in temperature.

Disposable filters must be replaced when the indicator shows restriction. Do not remove the part unless it is to be replaced, as this could damage the seal and thus compromise the engine's useful life. In filters that allow cleaning, the number of times this can be done depends on the manufacturer, but in general the secondary filter allows up to five cleanings. To clean it, tap it with your hands or on the tractor tire, without damaging the seal.

During periodic maintenance, check the transmission oil level and final reduction, top up if necessary. A low level causes systems to work poorly, causes overheating and accelerates wear. It is important to replace it within the deadlines established by the manufacturer, as over time, the lubricant loses its original characteristics. To make viewing easier, some manufacturers are replacing the dipsticks with displays on the tractor's body, so the producer has greater control of the situation.

Ballasting influences a tractor's performance and prevents premature wear, soil compaction and excessive fuel consumption. The procedure consists of adding or removing weights to the tractor to guarantee stability, grip and traction capacity, according to the operation that will be carried out, that is, observing weight (kg) per power (hp). A simple way to find out if the ballasting is correct is by observing the tracks left on the ground.

Hydraulic ballasting consists of adding water to the wheelsets; In metallic ballasting, fluids are added to the front part of the tractor and to the rear wheels, metallic masses made of steel or cast iron.

On 4x2 tractors with auxiliary front-wheel drive (TDA), the kinematic advance is intended to correct the difference in diameter between the front and rear wheels, where the front axle must rotate at a greater speed than the rear. The ideal range, according to the literature, is 1% to 5%. When values ​​are below 1%, TDA loses traction efficiency; above 5%, there is excessive wear on the front tires and a possible cause of Power Hop (gallop).

A practical and quick method for calculating kinematic advance is to measure five complete revolutions of the front and rear wheels, with the traction on and then with it off on firm ground. To do this, simply make a chalk mark on the front and rear tires, select a low gear and activate the differential lock. To count the starting point of the number of laps, when the mark touches the ground, a stake is placed marking this point. At the end of the fifth lap, mark this point with a stake, as done previously.

After that, measure the distance between the two stakes and apply the values ​​according to the equation below:

RD = Front wheel

When pulling implements, the tractor's wheels must necessarily slip. Slippage serves as an escape in the event of excessive effort on the part of the tractor. The recommended slippage for 4x2 tractors TDA is 8% to 15%. When slip rates are greater than 15%, there is a loss of traction efficiency and greater tire wear. To calculate the slippage on your property, mark a distance of 50 meters, and count the number of turns with the tractor performing operation and after the number of turns without load, that is, with the implement raised. The formula for calculating skating is as follows.

Another important point that influences the tractor's traction capacity, and which must be observed, is the weight distribution, where in 4x2 TDA tractors, the weight concentration on the front axle must be between 35% and 40%. To measure, simply use a road scale and measure the entire tractor and then the front axle. The weight percentage is the static distribution.

The correct use of an agricultural machine can generate significant savings in fuel consumption and, therefore, lower operating costs and greater profits, which is why it is essential to carry out maintenance correctly, following the periods and recommendations stipulated by the manufacturer.