The John Deere 955 compact utility tractor is a versatile and reliable machine designed for a wide range of tasks around the property, farm, or job site. This tractor, known for its durability and ease of use, is powered by a Yanmar 3TN84T-RJ diesel engine, providing ample power for tasks such as mowing, tilling, loader work, and snow removal. Understanding the specifications and capabilities of your 955 is crucial for ensuring optimal performance and longevity. The information contained within this manual will guide you through the proper maintenance procedures and troubleshooting steps to keep your tractor running smoothly for years to come. Familiarizing yourself with the tractor's key components, operating systems, and safety features will help you maximize its utility and minimize the risk of accidents or breakdowns.
The 955 boasts a hydrostatic transmission, offering smooth and responsive operation, making it ideal for tasks requiring precise speed control. The tractor's compact size and maneuverability allow it to navigate tight spaces with ease, making it a valuable asset in confined areas. This model also features a three-point hitch system, enabling the use of a variety of implements such as tillers, mowers, and box blades. Furthermore, the independent PTO (Power Take-Off) allows for powering implements independently of the tractor's ground speed, providing versatility for a wide range of applications. Proper understanding of the hydraulic system, electrical system, and drivetrain is essential for performing adequate maintenance and troubleshooting issues that may arise.
Operating and maintaining the John Deere 955 requires a thorough understanding of safety procedures to prevent accidents and injuries. Before operating the tractor, carefully read and understand all safety decals and the information provided in this manual. Always wear appropriate personal protective equipment (PPE), including safety glasses, hearing protection, and sturdy footwear. Ignoring safety warnings can result in serious injury or even death. Make sure to take your time and always be alert of your surroundings when operating the machine.
Before performing any maintenance or repairs on the 955, ensure that the engine is shut off, the parking brake is engaged, and the key is removed from the ignition. Disconnect the negative battery cable to prevent accidental starting. Never work under a tractor that is supported only by a jack; use jack stands for proper support. When working with hydraulic fluids, be aware of the high pressure and potential for injection injuries. Always relieve hydraulic pressure before disconnecting any lines. Failure to adhere to these safety precautions can lead to severe injury or damage to the tractor. Proper training and a commitment to safe practices are essential for operating and maintaining the John Deere 955 responsibly and effectively.
Removing the engine from your John Deere 955 is a significant undertaking, and safety should be your utmost priority. Before you even think about wrenching, disconnect the battery's negative terminal to prevent any accidental electrical shorts. Thoroughly inspect the area around the engine, identifying all hoses, wires, and linkages that connect it to the tractor's chassis. Carefully tag each connection with masking tape and a permanent marker – a simple sketch can also be invaluable – to ensure accurate reassembly later. Neglecting this step can lead to frustrating problems and potential damage down the line.
Begin by draining all fluids, including the engine oil, coolant, and fuel. Ensure you have appropriate containers to catch the fluids and dispose of them responsibly according to local regulations. Next, disconnect all electrical connections, fuel lines, and coolant hoses, carefully noting their positions and routing. Disconnect the exhaust system, the throttle linkage, and any other mechanical connections to the engine. Support the engine with a suitable hoist or engine stand before unbolting it from the tractor frame. This ensures the engine will not fall freely and risk causing damage or injury.
Once the engine is securely supported, carefully remove the mounting bolts and gently lift the engine from the tractor frame. Take your time and check for any remaining connections that may have been overlooked. With the engine removed, carefully place it on the engine stand and inspect the engine compartment for any signs of damage or wear. Installation is essentially the reverse of removal, but pay close attention to the torque specifications for all bolts and fasteners. Use a torque wrench and consult the service manual for the correct values. After installation, refill all fluids and double-check all connections before starting the engine. Bleed the fuel system and verify proper operation before putting the tractor back into service.
Disassembling engine components like the cylinder head, pistons, and crankshaft requires a clean workspace and the right tools. Start with the cylinder head. Before removing it, ensure the engine is cool to prevent warping. Remove all external components like the intake and exhaust manifolds, injectors, and rocker arms. Use a valve spring compressor to carefully remove the valves, making sure to keep each valve with its corresponding location. Inspect the cylinder head for cracks, warpage, and damaged valve seats. Clean all carbon deposits thoroughly using a suitable solvent and wire brush.
Next, move on to the pistons. After removing the cylinder head, turn the crankshaft until each piston is at its lowest point in the cylinder bore. Use a ridge reamer to remove any carbon buildup at the top of the cylinder bore. Remove the connecting rod caps and push the pistons out of the cylinders. Inspect the pistons for cracks, scoring, and excessive wear. Check the piston rings for wear and breakage. Measure the cylinder bores for out-of-roundness and taper using a bore gauge. Replace any components that are worn beyond the manufacturer's specifications.
Finally, address the crankshaft. With the pistons removed, you can remove the crankshaft bearing caps. Carefully lift the crankshaft from the engine block. Inspect the crankshaft journals for scoring, wear, and damage. Measure the journals for out-of-roundness and taper using a micrometer. Inspect the crankshaft bearings for wear and damage. If the crankshaft journals are significantly worn or damaged, the crankshaft may need to be reground by a professional machine shop. Always replace the crankshaft bearings with new ones during reassembly. Ensure proper lubrication during reassembly to prevent damage on startup.
The fuel system of the John Deere 955 is crucial for its smooth and efficient operation. A malfunctioning fuel injection pump or faulty injectors can cause a variety of problems, from poor starting to reduced power and excessive smoke. When working on the fuel system, cleanliness is paramount. Ensure your hands and tools are clean to prevent contamination of the sensitive fuel components. Always use clean fuel to prime the system after repairs.
The injection pump is responsible for delivering fuel to the injectors at the correct pressure and timing. To inspect the injection pump, remove it from the engine and visually check for leaks, damage, or worn components. If you suspect the pump is not functioning correctly, it's best to have it tested and repaired by a qualified fuel injection specialist. Tampering with the internal components of the injection pump without the proper tools and knowledge can lead to further damage. Injectors are responsible for atomizing the fuel and spraying it into the combustion chamber. To inspect the injectors, remove them from the engine and visually check for clogs, leaks, or damage.
A simple test to check an injectors function is to connect them to a test bench with a fuel source and check the spray pattern. If the spray pattern is irregular, the injector is clogged or damaged and needs to be cleaned or replaced. Before installing the injectors, ensure the injector nozzles are clean and free of any debris. It's always a good idea to replace the fuel filters regularly to prevent contaminants from reaching the injection pump and injectors. Be sure to bleed the fuel system after any fuel system work. Start by opening the bleed screw on the fuel filter housing and pumping the priming lever until fuel flows freely. Then, open the bleed screw on the injection pump and repeat the process.
The cooling system is essential for maintaining the engine's operating temperature within safe limits. Overheating can cause severe engine damage, so regular maintenance of the cooling system is crucial. The radiator dissipates heat from the coolant, preventing the engine from overheating. Inspect the radiator regularly for leaks, damage, and obstructions. Clean the radiator fins with compressed air to remove any debris that may be blocking airflow. If the radiator is severely clogged or damaged, it may need to be replaced.
The water pump circulates coolant through the engine and radiator. A malfunctioning water pump can cause overheating and engine damage. Check the water pump for leaks, noise, and play in the shaft. If the water pump is leaking or making excessive noise, it needs to be replaced. When replacing the water pump, always replace the gasket or O-ring to ensure a proper seal. Always verify the proper coolant level. Use a coolant mixture that meets the manufacturer's specifications.
Regularly flush the cooling system to remove any accumulated sediment and contaminants. Use a coolant flush solution and follow the manufacturer's instructions. After flushing the system, refill it with fresh coolant. Inspect the coolant hoses for cracks, leaks, and swelling. Replace any hoses that are worn or damaged. Check the thermostat to ensure it is opening and closing at the correct temperature. A malfunctioning thermostat can cause overheating or undercooling. Pressure test the cooling system to check for leaks. If you find any leaks, repair them immediately. A well-maintained cooling system will help ensure the long life and reliable operation of your John Deere 955 engine.
The lubrication system is vital for reducing friction between moving engine parts, preventing wear and tear, and extending the engine's lifespan. It consists primarily of the oil pump, oil filters, and oil passages. Neglecting the lubrication system can lead to catastrophic engine failure, so regular maintenance is essential. The oil pump is responsible for circulating oil throughout the engine.
To inspect the oil pump, remove it from the engine and visually check for wear, damage, and clogs. If you suspect the oil pump is not functioning correctly, it should be tested and repaired. The oil filters remove contaminants from the oil, preventing them from damaging engine parts. Change the oil filters regularly according to the manufacturer's recommendations. When changing the oil filter, always lubricate the new filter's gasket with clean oil before installing it. Inspect the oil pressure gauge to ensure the engine is maintaining adequate oil pressure.
Low oil pressure can indicate a problem with the oil pump, a clogged oil filter, or excessive engine wear. Check the oil level regularly and add oil as needed. Use the correct type and grade of oil recommended by the manufacturer. Regularly change the engine oil according to the manufacturer's recommendations. This helps to remove contaminants and maintain the oil's lubricating properties. Inspect the oil pan for leaks and damage. Repair any leaks immediately. A properly functioning lubrication system is essential for the long life and reliable operation of your John Deere 955 engine.
Understanding the electrical system of your John Deere 955 is crucial for proper maintenance and troubleshooting. Wiring diagrams and schematics are the roadmaps that guide you through the intricate network of wires, connectors, and components. These diagrams provide a visual representation of the electrical circuits, showing how each component is connected and how electricity flows through the system. Familiarizing yourself with the symbols and conventions used in these diagrams is essential before attempting any electrical repairs. A thorough understanding allows you to trace circuits, identify faulty components, and perform accurate repairs. Always consult the specific wiring diagram relevant to your tractor model and year for accurate information.
Proper use of wiring diagrams requires careful attention to detail. Each wire is typically labeled with a unique identifier that corresponds to the wiring diagram. These identifiers are often printed directly on the wire itself. This allows you to quickly and accurately locate specific wires within the system. Color codes are also commonly used to differentiate wires and simplify tracing circuits. Remember that electrical systems can be complex, and incorrect wiring can lead to serious damage or even injury. When using wiring diagrams, double-check all connections and ensure that you are working with the correct diagram for your specific tractor configuration. Patience and precision are key to successful electrical troubleshooting and repair.
The starting system is responsible for cranking the engine until it reaches a speed where it can run on its own power. This system consists primarily of the starter motor, the solenoid, the battery, and the associated wiring. The starter motor is a powerful electric motor that engages with the engine's flywheel to turn it over. The solenoid acts as a switch, using a small electrical signal from the ignition switch to engage the starter motor's high-current circuit. The battery provides the electrical power to operate the starter motor. Any issues with these components can prevent the engine from starting.
Troubleshooting starting system problems typically involves checking the battery voltage, the condition of the starter motor, and the functionality of the solenoid. A weak or discharged battery is a common cause of starting problems. The starter motor itself can fail due to worn brushes, damaged windings, or a faulty drive mechanism. The solenoid can also fail, preventing the starter motor from engaging. When diagnosing starting system issues, always start with the simplest checks first, such as verifying the battery voltage and ensuring that all connections are clean and tight. A systematic approach to troubleshooting will help you quickly identify the root cause of the problem.
The charging system maintains the battery's charge and provides power to the tractor's electrical accessories while the engine is running. The heart of the charging system is the alternator, which generates electrical current through electromagnetic induction. The voltage regulator controls the alternator's output voltage, ensuring that the battery is charged properly without being overcharged. A malfunctioning charging system can lead to a dead battery, preventing the tractor from starting. It can also damage the battery and other electrical components.
Regularly checking the charging system's output voltage is essential for preventing problems. Use a multimeter to measure the voltage at the battery terminals while the engine is running. The voltage should typically be between 13.5 and 14.5 volts. A voltage that is too low indicates a problem with the alternator or the voltage regulator. A voltage that is too high indicates a faulty voltage regulator. When troubleshooting charging system issues, also inspect the condition of the alternator belt and ensure that it is properly tensioned. A loose belt can cause the alternator to operate inefficiently, reducing its output voltage.
The lighting system provides illumination for safe operation, especially during nighttime or low-light conditions. This system includes headlights, taillights, turn signals, and other auxiliary lights. Properly functioning lights are crucial for visibility and safety. Burned-out bulbs, corroded connections, and damaged wiring can all cause problems with the lighting system. Regular inspection and maintenance of the lighting system are essential for preventing accidents.
When troubleshooting lighting system problems, start by checking the bulbs. Use a multimeter to test the bulbs for continuity. If the bulbs are good, check the wiring and connections for corrosion or damage. Pay close attention to the grounds, as a poor ground connection can cause various lighting problems. Use a wiring diagram to trace the circuits and identify any faulty components. Always replace damaged wiring and connectors to ensure reliable operation.
The instrument panel provides critical information about the tractor's operating conditions. This panel includes gauges that display engine temperature, oil pressure, fuel level, and other important parameters. Accurate readings from these gauges are essential for monitoring the tractor's performance and preventing damage. Malfunctioning gauges can provide misleading information, potentially leading to serious engine problems. Regular inspection of the instrument panel and gauges is crucial for maintaining the tractor's reliability.
When troubleshooting instrument panel problems, start by checking the wiring and connections to the gauges. Loose or corroded connections can cause inaccurate readings or prevent the gauges from working altogether. Use a wiring diagram to trace the circuits and identify any faulty components. If a gauge is consistently providing inaccurate readings, it may need to be replaced. Also, inspect the sending units that provide data to the gauges. These sending units can fail over time, causing the gauges to display incorrect information. A thorough inspection of the instrument panel and associated components will help you ensure that you are receiving accurate information about your tractor's operating conditions.
The hydraulic system on the John Deere 955 is the heart of its powerful functionality, enabling smooth and efficient operation of the loader, backhoe (if equipped), and other hydraulically driven components. At the center of this system is the hydraulic pump, typically a gear-type pump, responsible for generating the necessary fluid pressure to power these functions. The pump draws hydraulic fluid from the reservoir and delivers it, under pressure, to the hydraulic control valves. Understanding the pump's operation and maintenance is crucial for ensuring optimal performance and longevity of your 955. Regular inspection of the pump for leaks, unusual noises, or vibration can help identify potential problems early on, preventing more costly repairs down the road.
Hydraulic control valves, often referred to as spool valves, are the brains of the hydraulic system. These valves precisely direct the flow of pressurized hydraulic fluid to the appropriate cylinders, controlling the movement of the loader arms, bucket, and other attachments. Each valve spool corresponds to a specific function, such as raising the loader or tilting the bucket. Proper valve operation is essential for precise and responsive machine control. Maintaining clean hydraulic fluid and regularly inspecting the valves for leaks or sticking can significantly improve their performance and prevent malfunctions. Damaged or worn valves can cause sluggish response, jerky movements, or complete loss of hydraulic function, necessitating repair or replacement.
Hydraulic cylinders are the linear actuators of the system, converting the pressurized hydraulic fluid into mechanical force to move the loader arms, bucket, and other attachments. Each cylinder consists of a piston inside a cylindrical barrel, with hydraulic fluid entering and exiting the cylinder to extend or retract the piston rod. The cylinder rods are connected to the moving parts of the implement, allowing for controlled and powerful movement. The cylinders are built to withstand very high pressure but will require regular maintenance to stay functioning.
Regular inspection of the hydraulic cylinders is essential for identifying potential problems such as leaks, dents, or corrosion. Cylinder leaks can lead to reduced hydraulic pressure, decreased performance, and contamination of the surrounding environment. Dents and corrosion can damage the cylinder seals, causing leaks and premature wear. Replacing damaged or worn cylinder seals is a common maintenance task, requiring proper tools and techniques to ensure a leak-free repair. When overhauling a hydraulic cylinder, it's important to inspect the piston rod for damage and replace any worn or damaged components.
Hydraulic hoses and fittings are the arteries and veins of the hydraulic system, carrying pressurized hydraulic fluid between the pump, valves, cylinders, and reservoir. These components must be able to withstand high pressures and temperatures, as well as the rigors of outdoor operation. Hydraulic hoses are typically constructed of multiple layers of reinforced rubber or synthetic material, while fittings are made of steel or brass. Ensuring that the hoses and fittings are in good condition is critical for maintaining a leak-free and efficient hydraulic system.
Regular inspection of hydraulic hoses and fittings is crucial for detecting potential leaks, cracks, or abrasions. Leaks can lead to loss of hydraulic pressure, decreased performance, and environmental contamination. Cracks and abrasions can weaken the hoses, increasing the risk of rupture under pressure. When replacing hydraulic hoses, it's important to use hoses that are rated for the correct pressure and temperature. Always use the correct fittings and torque specifications when connecting hoses to prevent leaks. Properly routing and securing hydraulic hoses can also help prevent abrasion and damage.
Diagnosing hydraulic problems requires a systematic approach and a thorough understanding of the system's components and operation. Common hydraulic issues include loss of power, sluggish response, jerky movements, leaks, and excessive noise. Identifying the root cause of the problem can be challenging, as several factors can contribute to these symptoms. Using a process of elimination and relying on accurate diagnostic tools is important.
One of the first steps in troubleshooting hydraulic issues is to check the hydraulic fluid level and condition. Low fluid levels can cause cavitation in the pump, leading to reduced performance and noise. Contaminated fluid can damage hydraulic components and cause valve malfunctions. Another common cause of hydraulic problems is air in the system, which can cause spongy or erratic movements. Bleeding the air from the system can often resolve these issues. When troubleshooting hydraulic problems, it's important to consult the John Deere 955 service manual for specific troubleshooting procedures and diagnostic tips. Always follow proper safety precautions when working on hydraulic systems, as pressurized hydraulic fluid can be dangerous.
Removing the transmission from a John Deere 955 compact tractor requires meticulous attention to detail and a structured approach. Prior to commencing the removal process, it's absolutely crucial to disconnect the battery and thoroughly drain the transmission fluid. Failing to do so can result in electrical hazards and significant fluid spillage, complicating the repair process and creating a potential safety hazard. Securely support the tractor with jack stands positioned appropriately to prevent any accidental movement during the removal. Proper support is essential for a safe and efficient removal of the transmission.
The first step involves disconnecting all linkages, hoses, and wiring harnesses that are attached to the transmission. These components typically include shift linkages, hydraulic lines for power steering or auxiliary hydraulics, and electrical connectors for sensors or control systems. Carefully label each connection as you disconnect it; this will greatly simplify the reinstallation process and prevent errors that could lead to operational issues. Furthermore, take detailed photographs of the connections; these images can serve as an invaluable reference during reassembly, particularly if the repair process is interrupted or spans multiple days. Keeping this information organized will save time and prevent frustration in the long run.
With all connections detached, the next step is to unbolt the transmission from the engine and the rear axle housing. Depending on the model year and configuration, these bolts may be located in hard-to-reach areas. Using the appropriate sized socket and extension can greatly assist in accessing these fasteners. Once the bolts are removed, carefully separate the transmission from the engine and the rear axle housing. It is highly recommended to use a transmission jack to support the weight of the transmission during removal. A transmission jack provides stability and control, preventing accidental drops and potential damage to the transmission or surrounding components. Finally, slowly and methodically move the transmission away from the tractor, ensuring there are no remaining obstructions or connections.
Installation is essentially the reverse of the removal process. Before installation, carefully inspect all mating surfaces for cleanliness and any signs of damage. Use a gasket scraper to remove any old gasket material, and apply a thin coat of sealant to ensure a proper seal. Align the transmission with the engine and the rear axle housing, and carefully slide it into place. Use a transmission jack to maintain correct alignment and support the weight. Secure the transmission with the appropriate bolts, tightening them to the manufacturer's specified torque. Finally, reconnect all linkages, hoses, and wiring harnesses, referring to your labels and photographs to ensure proper connections. Refill the transmission with the correct type and amount of fluid, and double-check all connections before starting the tractor. Always verify proper operation after reinstallation.
Once the transmission is removed, gearbox disassembly is required to access internal components for inspection and repair. Start by thoroughly cleaning the exterior of the transmission case to prevent dirt and debris from entering during disassembly. A clean workspace is also important for preventing the loss of small parts. Consult the John Deere 955 service manual for detailed diagrams and instructions specific to your transmission model. These diagrams will be invaluable in identifying the location and orientation of each component.
Begin by removing the transmission case cover, carefully noting the orientation of any gaskets or seals. Examine the internal components for signs of wear, damage, or corrosion. Pay close attention to the gears, bearings, and shafts. Look for chipped or broken teeth on the gears, rough spots or discoloration on the bearings, and excessive play in the shafts. Any of these issues can indicate a need for replacement. Proper inspection requires a keen eye and attention to detail.
Carefully remove each gear, bearing, and shaft, keeping them organized and labeled. Consider using a parts tray or a system of labeled containers to prevent mixing up the components. Inspect each component thoroughly, using precision measuring tools such as micrometers and calipers to check for wear and dimensional inaccuracies. Compare your measurements to the specifications in the service manual to determine whether the components are within acceptable tolerances. Document any findings carefully.
Pay particular attention to the condition of the bearings. Check for smooth rotation, excessive play, and any signs of damage to the bearing races. If a bearing feels rough or gritty, it likely needs to be replaced. Similarly, inspect the seals for cracks, tears, or brittleness. Damaged seals can lead to fluid leaks and premature wear of the internal components. Replacing worn seals during the disassembly process is a preventative measure to ensure a long lifespan. Thorough inspection will identify areas that require attention and replacement.
The differential and axles are critical components responsible for transferring power from the transmission to the wheels. Problems in these areas can manifest as unusual noises, vibrations, or a loss of drive. Repairing these components requires careful disassembly, inspection, and replacement of worn or damaged parts. Start by removing the axles from the differential housing, using a suitable puller if necessary. Some axles are held in place by retaining rings or snap rings; be sure to remove these before attempting to pull the axle. Prior to any disassembly, make sure all necessary safety precautions are followed including but not limited to; eyewear and correct gloves.
Once the axles are removed, disassemble the differential housing. This will typically involve removing the differential carrier and associated components. Carefully inspect the differential gears for wear, damage, or broken teeth. Pay close attention to the pinion gear and ring gear, as these are subject to high stress. Check the bearings for smooth rotation and any signs of damage. Replacing worn bearings and gears is essential to ensure proper differential operation. Proper operation is very important as the differential is vital to the tractor's ability to turn.
Inspect the axle shafts for straightness, cracks, and wear on the bearing surfaces. Bent or cracked axle shafts must be replaced. Worn bearing surfaces can cause excessive play and premature bearing failure. Also, inspect the axle seals for leaks. Replace any damaged or worn seals to prevent fluid loss. Fluid loss can result in very expensive future repairs.
When reassembling the differential and axles, use new bearings and seals where necessary. Apply grease or oil to the bearing surfaces before installation. Torque all bolts to the manufacturer's specifications. Check the axle end play and adjust as necessary. Proper lubrication and correct torque settings are crucial for reliable operation. After reassembly, test the differential and axles for smooth operation before reinstalling them on the tractor. Ensuring correct function before reassembly into the machine will prevent future teardowns if a mistake has been made.
The clutch is responsible for engaging and disengaging the engine from the transmission. A slipping clutch can result in reduced power and poor performance. An improperly adjusted clutch can cause difficulty shifting gears or even damage to the transmission. Adjusting or replacing the clutch requires a precise procedure to ensure proper operation. First, inspect the clutch linkage for wear or damage. Worn linkages can cause inaccurate clutch engagement.
Adjust the clutch pedal free play according to the manufacturer's specifications. This adjustment ensures that the clutch fully engages and disengages. The free play measurement is usually found in the service manual. A small gap between the pedal and the engagement point is crucial for proper clutch function. Incorrect free play can cause clutch slippage or difficulty shifting.
If the clutch continues to slip even after adjustment, it may need to be replaced. Removing the transmission from the tractor is typically required to access the clutch assembly. Before removing the clutch, mark the orientation of the clutch disc to the flywheel. This will help ensure that the new clutch disc is installed correctly. Inspect the flywheel for wear or damage. A worn flywheel can cause clutch slippage and vibration.
When installing a new clutch disc, make sure it is properly aligned with the pilot bearing. Use a clutch alignment tool to ensure proper alignment. Torque the clutch pressure plate bolts to the manufacturer's specifications. Over-tightening the bolts can damage the pressure plate. After installing the new clutch, readjust the clutch pedal free play. A properly adjusted clutch will provide smooth engagement and reliable performance. Always test the clutch operation after completing the adjustment or replacement. A smooth transition and engagement is what you should look for when testing clutch performance.
The John Deere 955 utilizes a hydrostatic power steering system, which provides effortless maneuverability even in challenging terrain. This system is comprised of several key components working in harmony. These include the steering wheel, which initiates the steering action; a hydraulic pump, driven by the engine, that supplies the necessary pressure; a steering control unit (SCU), also known as an orbital valve, which meters the hydraulic fluid based on the steering wheel input; hydraulic cylinders, which translate the hydraulic pressure into mechanical force to turn the front wheels; and the associated hydraulic lines and reservoir that complete the closed-loop system. Understanding the function of each component is essential for proper maintenance and troubleshooting of the steering system. Ensure you consult the parts catalog for accurate component identification and part numbers when performing repairs.
Regular inspection of the steering system components is crucial for maintaining optimal performance and preventing costly repairs. Begin by visually inspecting all hydraulic lines for leaks, cracks, or signs of wear. Pay close attention to connections and fittings, ensuring they are tight and free from corrosion. Check the hydraulic fluid level in the reservoir and top it off as needed, using only the recommended John Deere hydraulic fluid. Next, inspect the steering cylinders for any signs of damage or leaks. A leaking cylinder will result in decreased steering performance and may require replacement or resealing. Lastly, confirm the steering wheel has appropriate free play and does not feel loose or jerky, as this may indicate a problem with the SCU.
The braking system on the John Deere 955 is a critical safety component, designed to provide reliable stopping power. It's important to understand that the 955 typically uses mechanical drum brakes, activated by foot pedals. These brakes rely on friction between the brake shoes and the brake drums to slow or stop the tractor. Over time, the brake shoes can wear down, or the drums can become glazed or contaminated, leading to reduced braking efficiency. Regular inspection and adjustment of the brake system are therefore essential to ensure safe operation of the tractor. Neglecting the brakes can result in dangerous situations, especially when operating on slopes or with heavy loads.
Proper adjustment of the brake pedals is vital for balanced and effective braking. Both brake pedals should be adjusted so they engage simultaneously and provide equal braking force. Begin by loosening the adjustment linkage and then adjusting the pedal travel until both pedals have the same amount of free play before engaging the brakes. Once the free play is equal, tighten the linkage and re-check the adjustment. If the brakes still feel uneven or spongy, it may be necessary to inspect the brake shoes and drums for wear or damage. Remember to consult the service manual for the correct specifications and adjustment procedures for your specific model.
If the brake shoes are worn beyond the acceptable limit, they must be replaced. The brake drums should also be inspected for scoring, glazing, or excessive wear. Light scoring can often be removed by lightly sanding the drums, but severely damaged drums may need to be resurfaced or replaced. When replacing brake shoes, always replace them in pairs to ensure equal braking performance. After replacing the brake shoes or drums, it is crucial to properly adjust the brake pedals to achieve the correct free play and braking balance. Failure to do so can lead to uneven braking and potentially dangerous situations.
Diagnosing steering and brake problems requires a systematic approach, starting with a thorough visual inspection and then progressing to more detailed testing. If the steering feels heavy or sluggish, begin by checking the hydraulic fluid level and inspecting the hydraulic lines for leaks or obstructions. A low fluid level can cause cavitation in the hydraulic pump, leading to reduced steering power. Next, check the steering cylinders for leaks or damage. A leaking cylinder will result in a loss of hydraulic pressure and reduced steering performance. If the problem persists, the steering control unit (SCU) may be faulty and require testing or replacement by a qualified technician.
Brake problems often manifest as uneven braking, spongy pedal feel, or a complete loss of braking power. Uneven braking can be caused by misadjusted brake pedals, worn brake shoes, or contaminated brake drums. Spongy pedal feel can indicate air in the brake lines or a faulty master cylinder. A complete loss of braking power is a serious safety hazard and requires immediate attention. Start by checking the brake fluid level and inspecting the brake lines for leaks. If the fluid level is low, or there are signs of leaks, the system needs to be bled to remove air. If the problem persists, the master cylinder or brake shoes may need to be replaced. Remember to consult the service manual for specific troubleshooting procedures and torque specifications.
When troubleshooting any steering or brake problem, always prioritize safety. Disconnect the battery before working on the electrical system. Wear appropriate safety glasses and gloves when handling hydraulic fluid or brake fluid. Properly support the tractor before working underneath it. And always follow the manufacturer's recommendations and specifications when performing any maintenance or repair work. If you are not comfortable performing the necessary repairs yourself, it is always best to seek the assistance of a qualified John Deere technician. Proper maintenance and repair of the steering and brake systems are essential for safe and reliable operation of the John Deere 955.
The John Deere 955, while primarily known as a compact tractor, is often enhanced with a loader attachment for tasks like moving materials, clearing debris, and general utility work. The loader typically consists of a bucket or forks, each serving different purposes. Regularly inspecting the loader arms, hydraulic cylinders, and pivot points is crucial for safe and efficient operation. Lubricate all grease fittings according to the maintenance schedule outlined in the general service section of this manual. Check for signs of wear, damage, or leaks in the hydraulic system, and address any issues promptly to prevent further damage or potential hazards. Properly maintained loader attachments significantly increase the versatility of your John Deere 955.
Specifically, when inspecting the bucket or forks, examine for dents, cracks, or bends. If the bucket’s cutting edge is worn or damaged, consider replacing it to maintain optimal digging and scooping performance. For fork attachments, ensure the tines are straight and properly aligned. Misaligned or bent forks can cause uneven lifting and increase the risk of dropped loads. Also, inspect the locking mechanisms that secure the attachments to the loader arms. These mechanisms should function smoothly and securely to prevent accidental detachment during operation. Regularly clean the loader and attachments to remove debris and dirt, which can accelerate wear and corrosion.
Many John Deere 955 owners utilize a mid-mount mower deck for maintaining lawns and fields. Proper mower deck maintenance is essential for achieving a clean, even cut and prolonging the life of the equipment. Before each use, inspect the blades for sharpness, nicks, and balance. Dull blades tear the grass, leading to unhealthy growth and an unsightly appearance. Sharpen the blades regularly using a grinding wheel or file, ensuring they are balanced to prevent excessive vibration. Replace blades that are significantly damaged or worn beyond repair.
Furthermore, inspect the mower deck housing for rust, cracks, or dents. Address any damage promptly to prevent further deterioration. Check the condition of the belts and pulleys, ensuring they are properly aligned and tensioned. Loose or worn belts can slip, reducing cutting performance and potentially causing damage to the mower deck. Lubricate all grease fittings on the mower deck according to the recommended maintenance schedule. Cleaning the underside of the mower deck regularly is crucial. Accumulated grass clippings can trap moisture, leading to rust and corrosion. Remove debris and dirt after each use to maintain optimal performance and prolong the life of the mower deck.
While not a standard feature, some John Deere 955 tractors are equipped with a backhoe attachment for digging and trenching tasks. The backhoe, if present, requires meticulous maintenance to ensure safe and efficient operation. Regularly inspect the boom, dipper stick, and bucket for signs of wear, cracks, or bends. Pay close attention to the pivot points and hydraulic cylinders, checking for leaks and proper function. Lubricate all grease fittings frequently, as the backhoe operates under significant stress and in often harsh conditions.
Ensure all safety features, such as the seat belt and rollover protection system (ROPS), are in good working order. Before operating the backhoe, thoroughly inspect the area for underground utilities and obstacles. Never dig without first verifying the location of buried lines to prevent damage and potential hazards. Proper operation techniques are crucial for both safety and efficiency. Avoid overextending the backhoe and always operate within the specified load limits. Practice smooth and controlled movements to prevent jerky motions and potential damage to the equipment or surrounding environment. Always retract and secure the backhoe properly when not in use.
The Power Take-Off (PTO) system is a vital component of the John Deere 955, used to power various implements such as rotary tillers, brush hogs, and post-hole diggers. Proper PTO system service is critical for safe and reliable operation. Before each use, inspect the PTO shaft and driveline for wear, damage, or missing shields. Damaged or missing shields can expose rotating parts, creating a significant safety hazard. Ensure the PTO shaft is properly connected and secured to both the tractor and the implement.
Lubricate the PTO shaft and driveline regularly according to the manufacturer’s recommendations. Use a high-quality grease specifically designed for PTO systems. Inspect the PTO clutch and brake system for proper function. The PTO clutch should engage and disengage smoothly, and the brake should stop the PTO shaft quickly when disengaged. Adjust or repair the PTO clutch and brake system as needed to ensure optimal performance and safety. Always disengage the PTO and shut off the engine before performing any maintenance or adjustments on the implement. Follow all safety precautions and operating procedures outlined in the implement’s owner’s manual.
Identifying and resolving common issues is crucial for maintaining the smooth operation of your John Deere 955. Before diving into complex diagnostics, it's always wise to start with the simplest potential causes. Regularly check fluid levels, including engine oil, hydraulic fluid, and coolant, as low levels can lead to performance degradation or even engine damage. Inspect belts for wear and tear, ensuring proper tension to prevent slippage and maintain the functionality of associated components like the alternator and water pump. Finally, examine the fuel system for any signs of leaks, blockages, or contamination, as these can significantly impact engine performance and fuel efficiency.
One frequently encountered problem is difficulty starting the engine. This can stem from a variety of factors, beginning with the battery. Ensure the battery is fully charged and that the terminals are clean and free of corrosion. A weak or dying battery will not provide the necessary power to turn over the engine. Also, check the starter motor for proper operation; listen for any unusual noises during engagement, which could indicate a faulty starter. Another common culprit is the fuel system; confirm that fuel is reaching the engine by checking the fuel filter and fuel lines for blockages. If the engine is still not starting, consider checking the glow plugs (if equipped) and the fuel injection system.
Effectively troubleshooting the John Deere 955 requires the use of several specialized tools. A multimeter is indispensable for testing electrical components, such as the battery, alternator, and sensors. It can be used to measure voltage, current, and resistance, helping to pinpoint electrical faults. A hydraulic pressure gauge is essential for diagnosing issues within the hydraulic system. By connecting the gauge to various points in the system, you can monitor pressure levels and identify leaks, blockages, or faulty hydraulic components. Proper diagnosis prevents unnecessary part replacements and saves valuable time.
Utilizing visual inspection techniques is also essential in troubleshooting. Examine all hoses, lines, and connections for leaks, cracks, or damage. Carefully inspect the engine for signs of overheating, such as steam or coolant leaks. Listen attentively for any unusual noises, such as knocking, grinding, or squealing, which can indicate specific mechanical problems. When performing visual inspections, it's also important to check the condition of filters, including air filters, fuel filters, and hydraulic filters. Clogged filters can restrict airflow and fluid flow, leading to reduced performance and potential damage. Remember to always consult the service manual for specific testing procedures and safety precautions.
Modern John Deere 955 tractors often incorporate electronic control units (ECUs) that monitor various engine and system parameters. When a fault is detected, the ECU will generate an error code, which can be accessed through the tractor's instrument panel or a diagnostic tool. It's crucial to consult the service manual to understand the meaning of each error code. Each code corresponds to a specific fault in the system, allowing you to quickly narrow down the potential causes of the problem. Attempting to repair without understanding the error codes will only waste time and potentially cause additional damage.
Understanding error codes is only the first step; proper interpretation is key to effective troubleshooting. For instance, an error code indicating a faulty sensor could be due to a problem with the sensor itself, the wiring harness, or the ECU. Therefore, it's important to perform a series of tests to isolate the root cause. Start by checking the wiring harness for continuity and shorts, ensuring that the sensor is receiving the correct voltage. If the wiring is intact, the sensor may need to be replaced. If replacing the sensor doesn't resolve the issue, the ECU itself may be faulty, requiring further investigation. Remember to always refer to the service manual for specific troubleshooting procedures and diagnostic charts for each error code.
Adhering to the recommended maintenance intervals is crucial for maximizing the lifespan and performance of your John Deere 955 tractor. Neglecting scheduled maintenance can lead to premature component failure, reduced efficiency, and costly repairs down the line. Consult the maintenance schedule in this manual, paying close attention to the hourly or calendar-based intervals for each task. Regular checks and services, even if the tractor hasn't reached the specified hours, are beneficial for identifying potential problems early. Remember to document all maintenance activities, including dates, hours, and any parts replaced, in a service log to track the tractor's history and aid in future troubleshooting.
The frequency of maintenance tasks can also be influenced by the operating conditions of your tractor. For instance, if you frequently operate in dusty or muddy environments, you may need to clean or replace air filters more often than the recommended intervals. Similarly, if you are using the tractor for heavy-duty tasks like tilling or plowing, you should consider more frequent inspections of critical components like the engine, transmission, and hydraulic system. Always prioritize safety when performing any maintenance task, and ensure the tractor is properly supported and all safety devices are in place before starting work. It is always better to be safe than sorry, as a mistake can ruin your John Deere 955.
Proper lubrication is the lifeblood of any mechanical system, and the John Deere 955 is no exception. The lubrication chart provides a detailed overview of all lubrication points on the tractor, specifying the type of lubricant recommended for each location. Using the correct lubricant is critical, as using the wrong type can lead to inadequate protection, premature wear, and even component failure. Pay close attention to the specific requirements for engine oil, transmission fluid, hydraulic fluid, and grease fittings. Different lubricants have different viscosities and additives designed for specific applications.
When lubricating the tractor, ensure that the lubrication points are clean and free of debris. Use a grease gun to apply grease to the fittings until fresh grease emerges, indicating that the old grease and contaminants have been flushed out. For oil changes, be sure to use the recommended grade of oil and replace the oil filter according to the maintenance schedule. Clean the area around the oil filter before removal to prevent dirt from entering the engine. Always dispose of used oil and filters properly, following local environmental regulations. If you have doubts about which oil to use, or any part of the lubrication process, it is recommended you seek a professional mechanic for advice.
Filters are essential for protecting the engine, transmission, and hydraulic systems from harmful contaminants. Regularly replacing filters according to the maintenance schedule will help maintain optimal performance and prevent costly repairs. The John Deere 955 typically has several filters, including air filters, oil filters, fuel filters, and hydraulic filters. Each filter plays a specific role in removing contaminants from the respective system. Consult the manual for the location and replacement procedures for each filter type. Make sure you have all the tools and materials you need to complete the job.
When replacing filters, always use genuine John Deere replacement parts or equivalent quality aftermarket filters. Using inferior filters can compromise their effectiveness and potentially damage the system they are designed to protect. Before installing a new filter, lightly lubricate the gasket with oil to ensure a proper seal. Tighten the filter to the recommended torque specifications to prevent leaks. After replacing a filter, check for leaks and monitor the system closely for any signs of malfunction. Always prime fuel filters before installation to prevent airlocks in the fuel system.
Regularly checking fluid levels is a simple yet crucial preventative maintenance task. Low fluid levels can lead to overheating, reduced performance, and potential damage to critical components. The John Deere 955 has several fluid reservoirs that need to be checked regularly, including the engine oil, coolant, transmission fluid, hydraulic fluid, and fuel. Consult the manual for the location of each fluid reservoir and the proper method for checking the fluid level. Ensure the tractor is on a level surface when checking fluid levels for accurate readings.
When checking fluid levels, pay attention to the condition of the fluid as well. Check if the fluid is the correct colour and thickness. Discolored or contaminated fluids can indicate a problem with the system and may require further investigation. If you notice any leaks, identify the source and repair them promptly. When topping off fluids, use the recommended type and grade for each system. Avoid overfilling fluid reservoirs, as this can also cause problems. Regular fluid level checks are a simple and effective way to prevent major problems and ensure the longevity of your John Deere 955 tractor.
Proper torque is absolutely critical for maintaining the integrity and performance of your John Deere 955 tractor. Using the correct torque values ensures that fasteners are tightened securely without being overstressed, which can lead to damage or failure. Always consult this torque specification guide before tightening any bolt, nut, or screw on your tractor. Remember to use a calibrated torque wrench to achieve accurate and consistent results. Failure to adhere to these specifications can result in loose connections, component malfunctions, or even catastrophic engine or transmission damage.
This section provides a comprehensive list of torque specifications for various components of your John Deere 955. The table is organized by component group (e.g., engine, transmission, hydraulics) and fastener size. All torque values are provided in both foot-pounds (ft-lbs) and Newton-meters (Nm) for your convenience. When tightening fasteners, it is recommended to follow a star pattern to distribute the clamping force evenly. This prevents warping and ensures a secure connection. Always double-check your work and re-torque fasteners after a short period of operation to compensate for any settling.
Before tightening any fastener, ensure that the threads are clean and free of debris. Lightly lubricate the threads with a suitable anti-seize compound to prevent galling and ensure accurate torque readings. Be particularly careful when working with aluminum components, as they are more susceptible to damage from over-tightening. If a torque value is not explicitly listed, refer to the general torque specifications table for the appropriate fastener size and grade. Remember, if in doubt, it's always better to err on the side of caution and tighten to the lower end of the recommended range.
The John Deere 955's electrical system is complex, encompassing starting, charging, lighting, and control circuits. A thorough understanding of the wiring diagrams is essential for troubleshooting electrical problems and performing repairs safely and effectively. These detailed diagrams provide a visual representation of all electrical components, wiring harnesses, and connections within the tractor. Understanding these diagrams will allow you to trace circuits, identify potential faults, and ensure proper operation of all electrical systems.
These wiring diagrams are color-coded for easy identification of different circuits. Each wire is labeled with its gauge and circuit number, allowing you to trace its path through the system. The diagrams also show the location of fuses, relays, switches, and other electrical components. Pay close attention to the grounding points, as a poor ground connection can cause a variety of electrical problems. These detailed images are the key to diagnosing many problems. A proper use of them can drastically cut repair time!
When working on the electrical system, always disconnect the battery's negative terminal to prevent accidental short circuits and electrical shocks. Use a multimeter to test for voltage and continuity before disconnecting or reconnecting any wires. Refer to the troubleshooting section of this manual for specific diagnostic procedures. If you are not comfortable working on electrical systems, it is recommended to consult a qualified electrician. Always remember safety is paramount when dealing with electrical components.
Maintaining your John Deere 955 requires the occasional replacement of worn or damaged parts. This comprehensive parts list provides detailed information about all the components of your tractor. Each part is listed with its official John Deere part number, a description, and an exploded view diagram showing its location within the assembly. Using the correct part number is crucial for ensuring that you order the correct replacement part for your tractor.
This parts list is organized by component group, making it easy to find the parts you need. Each section includes detailed illustrations to help you identify the correct part. When ordering parts, be sure to provide the complete part number to your John Deere dealer. Double-check your order before submitting it to ensure accuracy. You can also order parts online through the John Deere parts catalog, which offers convenient access to the latest part information and pricing.
In addition to the part number and description, this list also includes information on supersedence. Supersedence indicates whether a part has been replaced by a newer or improved version. Always order the superseding part when available, as it may offer improved performance or reliability. Keep this parts list handy for all your maintenance and repair needs. Always purchase genuine John Deere parts to ensure the best quality and fit for your tractor. These aftermarket parts sometimes can cause more damage than repair.
Certain maintenance and repair procedures on your John Deere 955 require the use of special tools. These tools are designed to facilitate specific tasks and ensure that they are performed correctly and safely. Using the correct special tools can save you time and effort, while also preventing damage to your tractor. This section provides a list of the special tools required for various procedures, along with their John Deere part numbers and a brief description of their purpose.
The list of special tools is organized by component group. Each tool is identified with its part number, a description of its function, and an illustration showing it being used. Before attempting any repair procedure, review this list to ensure that you have the necessary tools on hand. If you do not have access to the required special tools, it may be necessary to take your tractor to a qualified John Deere service technician.
Investing in the necessary special tools can pay off in the long run, especially if you plan to perform regular maintenance and repairs on your tractor. Special tools are designed to fit specific components and provide the leverage or precision needed to perform the task correctly. Attempting to use makeshift tools can be dangerous and may result in damage to your tractor. When purchasing special tools, be sure to obtain them from a reputable supplier. Always use the tools according to the manufacturer's instructions.