The 16 × 4 full-automatic power shift gearbox (16 × 4 PST gearbox) used by tractor is an advanced and mature full-power load shift gearbox. Since it was put into use in 1994, it has experienced various field operation tests and has been deeply trusted and praised by users. The 16 * 4 PST gearbox has the structural characteristics different from the traditional tractor gearbox. The special difference is that the electronic system controls the hydraulic clutch and brake to achieve simultaneous interpreting of different transmission speeds.

The unique design of 16F × 4R full power shift gearbox and advanced electronic controller realize the flexible shift function and reduce the impact. There is no need to cut off the power of the engine when shifting. It is more stable when shifting gears and more convenient for the driver to operate. In 2006, the factory made a revolutionary technical improvement on the gearbox, built-in closed-loop electronic control shift device, so that the gearbox has a better shift performance. So that the full power shift transmission can still have excellent sensitive shifting ability when encountering instantaneous high torque load. PST's advanced 16F × 4R full power shift gearbox works in coordination with other tractor control systems. Its unique full automatic shift function can shift automatically according to the change of working load in most working conditions, bringing about nearly 9% improvement in fuel economy. This kind of gearbox is also equipped with automatic downshift function at high temperature, which improves the reliability of the gearbox and greatly extends the service life of PST gearbox. Therefore, how to operate and use the 16 × 4 PST gearbox correctly is a key problem. According to the factory design requirements, years of field practice and user's use, the author summarizes the following precautions for the correct operation and use of the 16 × 4 PST gearbox of 8R Series tractors

(1) The driver must check the hydraulic oil level every shift, and add it to the standard marking in time when it is insufficient. It is strictly forbidden to carry out field operation in the state of oil shortage. However, excessive hydraulic oil should not be added, which will cause high temperature inside the gearbox and burn transmission components. Especially in the maintenance and inspection, in addition to checking the hydraulic oil level, the driver should also observe whether the color of the hydraulic oil is clean and normal, and whether there is blackening or emulsification deterioration? Check and confirm that if there is deterioration, it must be replaced in time.

(2) Strictly use hy gard that meets the technical standards of Deere company ™ Hydraulic oil, because the hydraulic oil that does not meet the standard will affect the power transmission performance of PST gearbox, and poor quality hydraulic oil will lead to the burning of transmission grinding elements. Therefore, the grade of hydraulic oil is very important. It is not allowed to add hydraulic oil that does not meet the technical standard at will, and it is not allowed to mix different brands and grades of hydraulic oil.

(3) The driver shall timely replace the hydraulic oil and filter in the gearbox according to the maintenance requirements in OM operation manual, and clean the hydraulic oil filter screen at the bottom of the gearbox and the precipitated impurities and dirt in the gearbox. The hydraulic oil replacement time can not be extended at will. Generally, the oil replacement time can be extended by 3% - 5% according to the maintenance schedule.

(4) The PST transmission of 8R tractor is a full power shift transmission. The driver does not need to use the clutch pedal for normal shift operation. However, when the locomotive meets the emergency and dangerous situation, and when the farm implements are attached or the tractor is operated in a narrow space, it is recommended to use the clutch pedal to realize the precise control of the tractor movement and ensure the safety of the tractor. The clutch pedal can also be used to shift gears in field operation, but it is required to increase or decrease gears step by step.

(5) When using the clutch correctly, the clutch pedal must be pressed to the bottom every time, It is forbidden for the driver to put his right foot on the clutch pedal from time to time during normal operation or transportation. Due to the turbulence caused by obstacles in the field or uneven road, the driver unconsciously frequently steps down the clutch pedal with his right foot, which will lead to the clutch "semi combined" state, and the pressure of the hydraulic system will be released intermittently When the temperature of the hydraulic oil rises, the system pressure is insufficient, which will cause high temperature burning of the transmission drum and friction plate, and seriously affect the service life of the PST transmission. In addition, when the tractor is going downhill or sliding, it is strictly forbidden to step on the clutch pedal, otherwise it may cause serious damage to the transmission.

（6）  When the transmission handle is placed in the "neutral" position, the brake pedal can be stepped down to implement the brake. If the driver operates the brake "in gear", the friction plate components of the clutch brake in the transmission will be seriously "burned" or the seals will be damaged, resulting in the pressure leakage of the hydraulic system. In serious cases, the clutch brake drum will be burned and the piston body will be cracked .

(7) In the operation of locomotive, it is necessary to observe whether the temperature of hydraulic oil is normal. Once the high temperature of hydraulic oil alarms, the locomotive must stop in time to check the cause of the fault. Especially, the driver should clean up the weeds and dirt on the radiator of hydraulic system in time. The locomotive must not be forced to work in the high temperature state of hydraulic oil. Because the high temperature of hydraulic oil will cause the "burning" of clutch brake grinding plate and internal oil seal rubber parts in the transmission, which will lead to the failure of the transmission and affect the service life of PST transmission.

(8) When the locomotive is maintained in each shift, the driver should carefully check the solenoid valve on the end cover of PST gearbox, the connecting wire of sensor and the plug-in connector for extrusion, fracture, serious wear or loose connector. Once found, it must be repaired in time to ensure the transmission PTP electronic control transmission system in good condition.

(9) The driver should operate and use 16 × 4 PST correctly Gearbox, according to the load of the locomotive in the field operation, should "increase gear" or "reduce gear" in time. Manual control of forced increase gear and overload of "forced operation" are strictly prohibited. This will make the friction plate components in the clutch or brake in the PST gearbox "slip" due to overload and aggravate wear, resulting in internal friction, system high temperature and burning other transmission components.

(10) According to the local soil working conditions, the "starting gear" gear is set correctly. The forward starting gear of 8R tractor is F7, and the reverse gear is R2. If the local working conditions of users are poor, the soil specific resistance is large, and the load of farm tools at the rear of locomotive traction is heavy, in order to protect the PST transmission, the driver should modify the starting gear setting in time, change to forward gear F5, reverse gear R1, This setting can reduce the overload of the locomotive when starting, so as to extend the service life of the PST transmission.

(11) It is necessary to pay attention to the reasonable matching of farm tools at the rear of 8R tractor. It is recommended that users buy the machines and tools that have been tested in the factory. These configurations have been confirmed as the best matching, so users do not have to worry about problems in use. If local farm tools are used, it is necessary to know whether the "three certificates" of farm tools to be matched are complete, whether the technical parameters are suitable for the bearing capacity of each gear of 8R tractor PST gearbox, and pay special attention to prevent the gearbox from being damaged by excessive resistance during operation. For example, the width of 8r-2704 tractor equipped with flat scraper is usually 4.0-4.2m, and the width of 8r-3204 tractor equipped with 4.5m. It is not allowed to select too wide, otherwise it will lead to long-term overload of locomotive field operation and damage to PST gearbox. Of course, farm tools can not match too small, which will cause 8R tractor power and fuel waste and low efficiency.

(12) Once the 8R PST transmission fails, the driver can not insist on the load operation or shift to other adjacent gears to continue the operation, which will aggravate the damage of the clutch brake friction plate, piston, inner gear drum and related parts. For example: after the C2 clutch is damaged, the F5, F7 and F9 locomotives can't walk or walk slowly. If the driver changes to other gears for forced operation, the internal transmission parts of the gearbox will be damaged. Once the internal oil pressure of the clutch brake leaks, the high temperature friction plate steel plate of the system will be seriously worn, especially the material fragments, metal scraps and rubber fragments burned by friction will enter the hydraulic system, resulting in high temperature of the system, stuck valve and other faults, and aggravating the pollution and deterioration of the hydraulic oil.

(13) When the driver cleans the gearbox of 8R tractor, he should use high pressure air as much as possible. If high pressure water gun is used to directly flush PTQ sensor, wire plug components and electronic controller components, the pressure of water gun should be controlled between 1.5-2.0 bar. When washing the wire connector, make sure that the spray angle of the water gun is 45-90 degrees with the wire and the connector, so as to prevent the "short circuit" fault of the electrical system caused by high-pressure water spraying into the connector.

(14) 8R tractor 16 × 4 PST gearbox calibration: (a) when the gearbox is disassembled, repaired and re installed, or the locomotive is found to have serious "shrugging" situation in the field operation, it needs to be calibrated. (b) When the PTQ controller and solenoid valve of PST gearbox are replaced with new parts due to faults, it is also necessary to calibrate the gearbox. (c) The user should use the standard transmission hydraulic oil in accordance with the maintenance requirements of Deere om operation manual. The brand and model of the hydraulic oil should not be changed at will. If the special hydraulic oil for Deere cold area is used, or the hydraulic oil model is changed for special reasons, but the technical parameters of the oil meet the standard, the PST transmission must be calibrated after the oil change.