Frequently Asked Questions

A PTO drive shaft is a crucial component in farming machinery. It transfers power from a tractor to various implements, such as balers, mowers, and grain mixers.

Here’s a breakdown of its functions:

• Power Transmission: It connects the tractor’s PTO to the implement, allowing the tractor’s engine to power the implement.
• Versatility: Used in a wide range of equipment, including hay balers, rotary mowers, and irrigation systems.

Durability: Designed to withstand the rigorous demands of agricultural work, ensuring reliable performance.

Identifying and measuring a PTO drive shaft involves a few key steps. Here’s a simple guide to help you:

Identifying the PTO Drive Shaft

1. Check the Type: PTO shafts come in different types, such as North American spline shafts and German and Italian profile tubes. Each type has various series options based on bearing diameter, cap-to-cap overall length, and snap rings.
2. Parts Identification: Familiarize yourself with the parts of the PTO shaft, including the internal and external yoke (connection to the tractor), universal joint, and guarding (safety chain and safety shield).

The Weasler website also has an interactive series finder to help identify your PTO drive shaft.  

Measuring the PTO Drive Shaft

1. Measure the Shaft Length:
• Ensure the shaft is in the closed position (smallest length).
• Use a measuring tape to measure from the outside of each yoke. This is the closed length.
2. Measure the Universal Joint:
• Measure the length from one outer end to the other.
• Record the width of one end of the universal joint.
3. Combine Measurements:
• Use both measurements to find the correct PTO series size for your tractor’s horsepower.
• You can refer to a PTO yoke size chart or use a PTO Series Discovery Tool for accurate sizing.

Additional Tips

• Safety First: Always ensure the safety guard is in place and in working order.

Know Your Implement Connection: Determine if you have a shear pin, clutch, or splined implement end.

The primary differences between North American (domestic) and metric PTO (Power Take-Off) drive shafts lie in their shapes and design characteristics:

North American (Domestic) PTO Drive Shafts:

• Shapes: Typically square, rectangular, hexagonal, or splined.
• Design Focus: These shapes are designed for robustness and durability, making them suitable for heavy-duty agricultural applications where ease of replacement and maintenance are important.
• Applications: Commonly used in North American farming equipment, where high torque loads are frequent.

Metric PTO Drive Shafts:

• Shapes: Often feature bell, lemon, or star shapes.
• Design Focus: These designs are engineered for constant velocity and reduced friction, which is beneficial in applications requiring smoother transitions under variable loads.
• Applications: More common in European machinery, where smoother telescoping movements and reduced friction are prioritized.

Both types serve the same fundamental purpose of transferring power from the tractor to the implement, but their design differences cater to the specific needs and conditions of their respective regions.

The main components of a PTO drive shaft include:

1. Drive Shaft: This is the central component that transmits power from the tractor to the implement.
2. Universal Joint: These joints allow the drive shaft to flex and accommodate movement between the tractor and the implement.
3. Yoke: The yoke connects the drive shaft to the tractor and the implement.
4. Safety Guard: This is an important safety feature that covers the rotating parts to prevent accidents.

Each of these components plays a crucial role in ensuring the efficient and safe transfer of power.

Vibration in a PTO drive shaft can be caused by several factors:

1. Misalignment: Incorrect alignment of the drive shaft can lead to vibrations. This includes improper angles between the drive shaft and the equipment it connects to.
2. Worn or Damaged U-Joints: Universal joints (U-joints) that are worn out or damaged can cause vibrations. These joints need to be in good condition to function smoothly.
3. Loose Components: Any loose parts or components in the drive shaft assembly can contribute to vibrations.
4. Bent Shaft: A bent or damaged shaft can cause significant vibrations.

To prevent and fix these vibrations, you can:

1. Check Alignment: Verify that the drive shaft is correctly aligned with the equipment. Adjust the angles if necessary to ensure proper alignment.
2. Inspect and Replace U-Joints: Regularly inspect the U-joints for wear and damage. Replace them if needed.
3. Tighten Loose Components: Check for any loose parts in the drive shaft assembly and tighten them.
4. Replace Bent Shaft: If the shaft is bent, it should be replaced to eliminate vibrations.

Regular maintenance and inspections can help identify and prevent these issues and ensure smooth operation of your PTO drive shaft.

Weasler shafts are designed to be highly versatile and compatible with a wide range of tractors and implements. They offer different types of drive shafts to meet various needs:

1. Standard Drive Shafts: Suitable for applications like rotary cutters, tillers, and fertilizer spreaders. These are designed for occasional duty cycles and can handle up to 80 horsepower.
2. Classic Drive Shafts: Ideal for rotary cutters, combine headers, balers, mower conditioners, mixer feeders, and manure spreaders. These can handle up to 170 horsepower for intermittent duty cycles.
3. Professional Drive Shafts: Built for continuous duty cycles, suitable for combines, forage harvesters, balers, and other heavy-duty equipment. These can also handle up to 170 horsepower.

Weasler shafts come with various yoke options and telescoping profiles to ensure compatibility with different equipment. However, it’s always a good idea to check the specific requirements of your tractor and implement to ensure the best fit.

PTO drive shafts are equipped with several safety features to prevent accidents and injuries. Here are some key safety features and how they work:

1. PTO Guard: This is a protective cover that surrounds the PTO shaft. It prevents accidental contact with the rotating shaft, reducing the risk of entanglement with clothing, jewelry, or hair.
2. Shear Pin: This device is designed to break if the PTO shaft becomes jammed or overloaded. By breaking, it prevents damage to the driveline and reduces the risk of injury.
3. Slip Clutch: This mechanism allows the PTO shaft to slip if there is a sudden increase in load, preventing damage to the equipment and reducing the risk of injury.
4. Overrunning Clutch: This feature allows the implement to continue rotating after the tractor PTO is disengaged, preventing the implement from driving the tractor.
5. Telescoping Shaft: This allows the PTO shaft to adjust its length to accommodate different equipment setups, ensuring proper alignment and reducing stress on the driveline.
6. Universal Joints: These joints allow the PTO shaft to flex and bend, accommodating different angles between the tractor and implement. Proper maintenance and inspection of these joints are crucial for safe operation.

Regular inspection and maintenance of these safety features are essential to ensure their effectiveness. Always follow the manufacturer’s guidelines and safety recommendations when using PTO drive shafts.

Weasler offers a range of cut-to-length drive shafts, particularly for PTO applications. These drive shafts are designed for heavy-duty use in agriculture and other industries. Here are some key features:

• Design Adjustability: The drive shafts can be cut to the desired length to fit specific applications. Here is a video to help guide you.
• Interchangeability: They are compatible with most competitor models. Here is a make/model finder to show compatibility.
• Profiles Available: Tri-lobe, lemon, and star shaft profiles.
• Easy Lock Guard Construction: This allows for quick and easy assembly or removal with simple tools.

Our website has a resources section with access to product guides, instructional manuals, service and maintenance instructions, and more. If you cannot find what you’re looking for you can reach out to our technical support team as well.

Storing a PTO drive shaft properly when not in use is crucial to maintain its performance and longevity. Before storing, clean the drive shaft thoroughly with a penetrating oil and a wire brush to remove any debris or rust. Inspect it for any signs of wear, cracks, or other damage. If any damage is found, repair or replace the shaft before storage.