PTO Shaft for Bush Hog Flexwing Mowers 3710, 3715, 13710, 13715, 3810, 3815, 4815, 2820

Надежный вал отбора мощности для косилок Bush Hog Flexwing различных моделей.

PTO Shaft for Bush Hog Flexwing Mower Model: 3710, 3715, 13710, 13715, 3810, 3815, 4815, 2820

CMN Transmission manufactures a high-performance PTO shaft for Bush Hog flexwing mowers designed to fit models 3710, 3715, 13710, 13715, 3810, 3815, 4815, and 2820. This agricultural PTO shaft delivers reliable rotational power from your tractor's power take-off to the mower's cutting deck, ensuring smooth, uninterrupted operation across wide swaths of terrain. Whether you are managing large pastures, clearing roadside vegetation, or shredding crop residue after harvest, this flexwing mower PTO shaft is engineered to handle the demanding torque and speed requirements of commercial-grade mowing applications. Each shaft assembly undergoes rigorous quality testing at our ISO9001-certified facility before shipment, ensuring consistent performance under heavy workloads.

As a direct replacement of Bondioli & Pavesi PTO shaft assemblies, this tractor PTO shaft offers CAT4 and CAT5 configurations with constant velocity (CV) main shaft options. The PTO drive shaft supports multiple tractor spline sizes including 1.375"-6, 1.375"-21, and 1.750"-20, making it compatible with a broad range of tractors. Equipped with a two-disc slip clutch PTO shaft rated at 1200 Nm, it protects your mower gearbox and tractor PTO from sudden shock loads encountered during heavy mowing. This heavy duty PTO shaft is ideal for agricultural contractors, municipal crews, and farm operators who demand dependable power transmission in the field.

Технические характеристики

Вариант главного вала 1: CAT4 / CAT5, скоростной.

Вариант 2 для главного вала: промежуточный вал к стандартному валу отбора мощности CAT5.

Варианты центрального вала: CAT 4

Вал распределителя мощности имеет шлицы 1,750-20, а центральный редуктор — 1,375-6. Диаметр центрального вала варьируется в зависимости от модели.

Двухдисковое сцепление CAT 4 для вала 1.375-6

РАЗМЕР 6 FFV42 *1.375-6 * 1200 нм * Муфта

Валы крыла: Категория 4

Это означает, что на распределительном узле используется шлицевое соединение 1,75"-20, а на внешних коробках — 6-шлицевое сцепление 1,375"-6 (2 диска). Возможны и другие комбинации.

Характеристики вала отбора мощности для косилки Bush Hog Flexwing

• Constant Velocity (CV) Main Shaft
  The CV joint design on this PTO driveline shaft maintains uniform rotational speed regardless of the operating angle between tractor and mower, eliminating vibration and reducing wear on bearings and gearbox components. This is critical for flexwing mowers that articulate over uneven ground, ensuring consistent blade speed across all three decks.
• Two-Disc Slip Clutch Protection (1200 Nm)
  The integrated slip clutch PTO shaft provides overload protection with a 1200 Nm torque rating. When the mower encounters sudden obstructions such as rocks, stumps, or thick brush, the clutch discs slip to absorb the shock, protecting the tractor PTO output shaft, gearbox internals, and driveline components from costly damage.
• Multi-Spline Compatibility
  This tractor PTO drive shaft supports three common spline profiles: 1.375"-6, 1.375"-21, and 1.750"-20. This broad compatibility means you can pair it with tractors from major brands without requiring additional PTO shaft adapter components. Whether you run a 60 HP or 90 HP tractor, there is a matching CAT4 or CAT5 configuration.
• Heavy Duty PTO Shaft Tube Construction
  The PTO shaft tubing is manufactured from high-strength alloy steel that has been precision-drawn and heat-treated. This delivers superior torsional strength and fatigue resistance compared to standard mild steel tubes. The result is a heavy duty PTO shaft capable of sustained operation in demanding conditions including thick grass, weeds, and light brush.
• Precision-Machined Universal Joints
  Every PTO shaft universal joint in this assembly is forged from chromium alloy steel with needle roller bearings and permanent grease seals. These PTO shaft u joint components deliver long service life and smooth articulation, maintaining reliable power transfer even when the mower wings flex at steep angles during operation over ditches and hillsides.
• Integrated Safety Shield & Guard
  Each PTO shaft cover and guard tube is included with the assembly. The full-length rotating shield protects operators from contact with the spinning shaft, meeting international safety standards. Free-spinning cone guards at each end prevent clothing or debris from entangling around the PTO shaft yoke connections, reducing the risk of accidents during field operation.

Working Principle of Flexwing Mower PTO Drive Shaft

The PTO shaft for flexwing mower systems operates as a mechanical link that transfers rotational energy from the tractor's power take-off (PTO) output stub to the mower's power divider gearbox. When the operator engages the tractor PTO, the engine's crankshaft drives a secondary output shaft through the tractor's transmission, spinning it at a standardized 540 PTO shaft speed of 540 revolutions per minute. This rotating output stub connects to the main shaft of the PTO driveline shaft assembly through a splined coupling.

The main shaft, configured as a constant velocity (CV) joint, transmits this rotation to the mower's central power divider gearbox. The CV joint is essential in flexwing mower applications because the mower deck is pulled behind the tractor and frequently operates at varying horizontal and vertical angles. A standard single-joint PTO drive shaft would produce pulsating, uneven speed at these angles, causing vibration and premature component wear. The constant velocity design eliminates this issue by maintaining uniform output speed regardless of angular deflection, resulting in smooth, balanced power delivery.

Once rotational energy reaches the central power divider gearbox, it is split into three separate outputs: one for the center cutting deck and one for each wing deck. The center shaft and wing shafts, both configured as CAT 4 PTO drive shafts, carry power outward to each individual gearbox mounted on the mower frame. Each wing shaft includes a two-disc slip clutch at the gearbox end, providing overload protection independently for each cutting section.

The PTO shaft with slip clutch mechanism functions as a torque limiter. Under normal cutting conditions, friction between the clutch discs locks them together, transmitting full torque to the gearbox. When an obstruction causes torque to spike beyond the 1200 Nm threshold, the discs begin to slip against each other, absorbing the shock energy as heat rather than transmitting it to the drivetrain. Once the obstruction clears, the clutch re-engages automatically and normal operation resumes.

Throughout the entire driveline, PTO shaft universal joint assemblies at each connection point allow angular articulation between shaft sections. The needle roller bearings within each U-joint minimize friction loss while accommodating the constant movement inherent to flexwing mower operation. This interconnected system of main shaft, center shaft, wing shafts, clutches, and universal joints creates a complete, reliable power path from tractor to cutting blades.

Applications of Flexwing Mower PTO Shaft

1. Управление растительными остатками
After harvesting corn, soybeans, cotton, or sorghum, this PTO shaft for Bush Hog flexwing mowers powers the mower to shred standing stalks and residue across wide swaths. Efficient residue management accelerates decomposition, returns nutrients to the soil, and prepares fields for the next planting cycle. The 540 PTO shaft delivers consistent blade speed to handle tough, dry stalks without bogging down.

2. Roadside Vegetation Control
Municipal departments and highway maintenance contractors use Bush Hog flexwing mowers powered by this tractor PTO shaft to control vegetation along roads, medians, and drainage ditches. The wide cutting width of flexwing mowers combined with this reliable PTO driveline shaft allows crews to maintain miles of roadside in a single pass, improving visibility for drivers and reducing fire hazard from overgrown dry grass.

3. Orchard and Vineyard Management
In orchards and vineyards, undergrowth between tree rows must be kept short to reduce pest habitat and facilitate harvesting. This flexwing mower PTO shaft provides dependable power transfer for mowing between widely spaced rows. The slip clutch protects against unseen root balls and fallen branches, while the CV joint maintains smooth operation as the mower navigates undulating orchard floor terrain.

4. Pasture Management
Livestock operations rely on well-maintained pastures for grazing efficiency. This agricultural PTO shaft drives the flexwing mower to clip pastures evenly, controlling weeds like thistle and ragweed while encouraging dense, nutritious regrowth of desirable forage species. Regular mowing with this heavy duty Вал отбора мощности system helps prevent pasture degradation and supports healthier livestock feeding across large acreage properties.

5. Grass Maintenance
Airports, sports complexes, utility corridors, and large commercial properties require regular grass cutting across expansive areas. Bush Hog flexwing mowers powered by this PTO shaft tractor connection offer the productivity needed to maintain these vast spaces. The custom PTO shaft configuration options allow precise matching to different tractor setups, ensuring optimal performance regardless of the specific facility layout or terrain conditions.

6. Row Crop Stalk Shredding
After combine harvesting, row crop fields are left with tough stubble and stalk material that interferes with tillage and planting equipment. This PTO drive shaft reliably powers the mower to pulverize stalks down to ground level, supporting no-till and conservation tillage practices. The shear bolt PTO shaft or slip clutch protection ensures that hidden debris in the field does not result in expensive drivetrain repairs.

Как установить вал отбора мощности на косилку Bush Hog Flexwing

Step 1: Safety Preparation
Before beginning installation, park the tractor on level ground and turn off the engine. Engage the parking brake and place wheel chocks behind the rear tires. Remove the key from the ignition to prevent accidental startup. Allow any hot components to cool. Wear appropriate personal protective equipment, including heavy work gloves and safety glasses. Verify that the old PTO shaft parts have been fully removed and that the tractor PTO output stub is clean and undamaged.

Шаг 2: Проверка совместимости шлицов
Check the spline profile on your tractor's PTO output stub. This tractor PTO shaft is available in 1.375"-6, 1.375"-21, and 1.750"-20 spline configurations. Count the spline teeth and measure the shaft diameter to confirm you have the correct PTO shaft yoke size. Attempting to force an incompatible spline will damage both the yoke and the tractor PTO output.

Step 3: Check Shaft Length
Position the mower behind the tractor in its normal working configuration. Measure the distance between the tractor PTO stub and the mower's power divider input shaft. The PTO shaft tube must have adequate overlap in its telescoping sections throughout the full range of mower movement, including transport, raised, and lowered positions. Minimum overlap should be at least 6 inches (150 mm) in any position to maintain structural integrity and prevent the shaft halves from separating during operation.

Step 4: Lubricate and Connect the Tractor End
Apply a thin coat of lithium-based grease to the tractor PTO output stub splines. Slide the input PTO shaft yoke onto the tractor PTO stub until the spring-loaded locking pin clicks into the groove. Pull back on the collar to verify that the locking pin is fully engaged and the yoke cannot be pulled off the stub. This connection must be secure before proceeding.

Step 5: Connect the Implement End
Grease the mower's power divider input shaft splines. Slide the implement-end yoke of the PTO drive shaft onto the input shaft and engage the locking pin. For the wing shafts with slip clutch ends, ensure the clutch assembly is properly seated on the gearbox input shaft. Tighten any retaining hardware to the manufacturer's specified torque.

Step 6: Install Safety Shields
Slide the PTO shaft cover guard tubes into position over the shaft. Secure the shield retention chains to the tractor drawbar and mower frame to prevent the guards from rotating with the shaft. Verify that the cone guards at each end spin freely and are not contacting any fixed structure.

Step 7: Final Inspection and Test
Walk around the complete driveline assembly and inspect every connection point. Ensure all locking pins are engaged, guards are secured, and there is adequate clearance between the shaft and any hoses, wires, or frame members. Start the tractor and engage the PTO at low RPM. Listen for unusual noise or vibration. Gradually increase to full operating speed and observe the PTO shaft universal joint angles to confirm smooth rotation. Shut down and re-check all fasteners after the initial 15 minutes of operation.

How to Choose the Right PTO Driveline Shaft for Flexwing Mower

1. Match the Mower Model
Start by confirming your exact Bush Hog model number: 3710, 3715, 13710, 13715, 3810, 3815, 4815, or 2820. Each model has specific shaft length, end configuration, and clutch requirements. Using a PTO shaft for flexwing mower that is not matched to your model can result in improper fit, poor performance, and potential damage to the mower or tractor.

2. Identify Your Tractor's PTO Spline
Check whether your tractor has a 1.375"-6, 1.375"-21, or 1.750"-20 PTO output stub. This determines which PTO shaft yoke end you need. Mismatched splines will not engage properly. If you are unsure, count the spline teeth on the stub and measure its diameter with calipers, or consult your tractor owner's manual for the specification.

3. Determine Horsepower Category
Select CAT 4 if your tractor produces up to 60 HP at 540 RPM, or CAT 5 for tractors up to 90 HP at 540 RPM. The category determines the PTO shaft sizes, series rating, and overall strength of the driveline. Under-sizing the shaft category for your tractor's output will lead to premature failure, while over-sizing adds unnecessary weight and cost.

4. Select Main Shaft Type
Choose between the constant velocity (CV) main shaft for smoother operation at variable angles, or the jack shaft to standard CAT5 configuration for a more economical setup. The CV option is recommended for operators who work on uneven terrain or need reduced vibration. This choice directly impacts the longevity of your PTO shaft u joint components and overall comfort.

5. Confirm Clutch Requirements
The standard configuration includes a two-disc slip clutch rated at 1200 Nm on each wing shaft. If your operation involves frequent encounters with heavy debris, consider a PTO shaft shear bolt option as an alternative or supplemental protection device. The shear pin PTO shaft style uses a replaceable shear bolt that breaks under overload, providing a simple and inexpensive safeguard.

6. Consider Custom Configurations
CMN Transmission supports full OEM customization. If your setup requires non-standard shaft lengths, special PTO shaft adapter connections, or unique clutch torque settings, contact our engineering team for a custom PTO shaft solution. We can modify PTO shaft tubing lengths, yoke profiles, and clutch specifications to fit your exact requirements.

Common Troubleshooting for Tractor PTO Shaft Issues

• Excessive Vibration During Operation
  If you notice severe vibration when the PTO drive shaft is engaged, the most common cause is worn or seized PTO shaft u joint bearings. Inspect each universal joint by hand, checking for rough spots or binding in the bearing caps. Replace any joint that does not rotate smoothly. Additionally, check the PTO shaft tube for dents or bends, as even minor damage to the tubing can cause significant imbalance at operating speed. Finally, verify that the shaft is the correct length for your setup. An excessively compressed or extended telescoping shaft will operate at a steep angle that exceeds the U-joint's design limit.
• Slip Clutch Engaging Too Frequently
  If the slip clutch slips under normal cutting loads (not obstructions), the clutch discs may be worn, contaminated with oil, or incorrectly adjusted. Remove the clutch assembly and inspect the friction discs for glazing, scoring, or reduced thickness. Replace the discs if they are below the minimum specification. If the discs appear serviceable, clean them with a solvent to remove any grease or oil contamination. After reassembly, adjust the clutch spring preload according to the manufacturer's torque specification of 1200 Nm to restore proper engagement.
• Shaft Disconnects or Pops Off
  If the PTO shaft yoke disengages from the tractor PTO stub during operation, the locking pin or collar mechanism is likely worn or damaged. Inspect the spring-loaded lock pin for wear, breakage, or rust that prevents full engagement. Replace damaged pins immediately. Also check that the groove on the tractor PTO stub is not worn or rounded, as this can prevent the pin from locking securely. Always test the lock by pulling firmly on the yoke after connection.
• Unusual Noise (Clunking or Knocking)
  A rhythmic clunking noise typically indicates excessive play in the universal joints or spline connections. Grip the shaft near each joint and check for angular free play. Any noticeable looseness means the PTO shaft universal joint bearings are worn and must be replaced. Spline wear in the telescoping shaft section can also produce a knocking sound under load. Inspect the internal and external spline profiles for visible wear and replace the affected shaft section if backlash exceeds 2 degrees.
• Shear Bolt Failures
  Repeated PTO shaft shear bolt breakage suggests that the mower is encountering loads beyond the shear bolt's design limit, the PTO is being engaged too aggressively, or the bolt specification is incorrect. Ensure you are using the correct shear bolt grade and size. Engage the PTO at low RPM and gradually increase to operating speed. If bolts continue to fail during normal mowing, the blade assembly may be out of balance or the cutting height may be set too low for the terrain conditions.
• Poor Power Delivery or Sluggish Blade Speed
  If the mower blades spin slower than expected, first confirm the tractor PTO is set to the correct 540 RPM output speed. Check the telescoping shaft splines for binding caused by lack of lubrication or corrosion. A seized telescoping joint prevents the shaft from extending properly and can reduce effective power transfer. Clean and grease the splines with a lithium-based grease. If power delivery remains poor, inspect the PTO shaft cover guards to ensure they are not contacting the rotating shaft and creating drag.

CMN Transmission vs. Other PTO Shaft Brands

See how CMN Transmission's agricultural PTO shaft solutions compare to well-known industry brands.