Volvo A35E Transfer Box: Understanding its Role and Common Issues

[MikePhua]

The Volvo A35E is part of Volvo's renowned A-Series of articulated haulers, known for their durability, power, and efficiency in tough off-road conditions. The A35E, with its impressive hauling capacity, is a vital asset for construction, mining, and other heavy-duty applications. One of the critical components that ensures the vehicle's performance and reliability is the transfer box, a crucial part of the drivetrain. In this article, we’ll delve into the role of the transfer box in the A35E, common issues, troubleshooting steps, and maintenance tips.
The Role of the Transfer Box in the Volvo A35E
The transfer box in an articulated hauler like the Volvo A35E is a key element of its drivetrain. It’s responsible for distributing the engine's power to both the front and rear axles, ensuring the truck maintains its all-wheel drive functionality. The transfer box connects to the vehicle's transmission and is typically powered by the engine's output shaft.
The purpose of the transfer box is to evenly distribute torque to the axles, enabling the hauler to perform optimally, even in challenging terrain. For articulated haulers like the A35E, which are designed to navigate steep inclines, loose soil, and rough landscapes, the efficient operation of the transfer box is crucial for maintaining stability and power distribution.
Common Issues with the Volvo A35E Transfer Box
Though robust, the transfer box in the Volvo A35E is subject to wear and tear, especially in extreme operational conditions. Some common issues that owners and operators might face include:

1. Leaks: Over time, seals and gaskets in the transfer box can wear out, leading to oil leaks. Leaking oil not only decreases the performance of the transfer box but can also cause it to overheat, leading to potential failure.
   
2. Transfer Box Overheating: The transfer box is susceptible to overheating, especially when the vehicle is working in high-demand environments. If the oil in the transfer box becomes too hot, it can cause the internal components to wear prematurely, reducing the lifespan of the component and affecting overall performance.
   
3. Strange Noises: Unusual noises coming from the transfer box, such as grinding or whining, can be a sign of damaged gears or bearings. These noises are often caused by inadequate lubrication or excessive wear, which can result in component failure if not addressed promptly.
   
4. Difficulty in Engagement: If the transfer box is having trouble engaging or disengaging, it may indicate issues with the internal shifting mechanism or a problem with the control system. This could affect the vehicle’s ability to switch between driving modes or gears properly.
   
5. Excessive Vibration: A malfunctioning transfer box may cause excessive vibration during operation. This can be caused by worn-out bearings, damaged gears, or imbalanced components, which can affect the vehicle’s overall handling.
   

Troubleshooting the A35E Transfer Box
When issues arise with the transfer box in the Volvo A35E, it’s important to identify the root cause to ensure a quick and effective repair. Below are some steps to troubleshoot common transfer box problems:

1. Check for Oil Leaks: The first step is to inspect the transfer box for any visible signs of oil leakage. Leaking oil can reduce the lubrication inside the transfer box, leading to increased wear and potential overheating. Replace worn seals and gaskets to stop the leaks, and ensure that the transfer box is properly filled with the correct oil type.
   
2. Monitor Oil Temperature: Keep track of the oil temperature, especially during heavy-duty operations. If the oil temperature rises above the recommended range, the transfer box is at risk of overheating. Use proper cooling measures and consider installing an oil cooler if the transfer box frequently operates in high-temperature conditions.
   
3. Inspect for Unusual Noises: If you hear any grinding or whining sounds, it’s crucial to inspect the transfer box for worn-out gears or bearings. To prevent further damage, replace the faulty parts as soon as possible. It’s also a good idea to check the oil levels to ensure proper lubrication.
   
4. Check Engagement Mechanism: If the transfer box is not engaging properly, the first step is to inspect the control system and the linkage for any issues. If the problem lies within the internal mechanisms of the transfer box, it may require disassembly to examine the shifting forks and the synchronizing parts for wear.
   
5. Vibration Analysis: If the hauler experiences excessive vibration, it could indicate an imbalance in the transfer box components. Inspect the transfer box for any damaged or misaligned parts, and replace them if necessary. Additionally, ensure that the transfer box is properly aligned with the rest of the drivetrain.
   

Maintenance Tips for the Volvo A35E Transfer Box
Regular maintenance is key to ensuring the transfer box in the Volvo A35E remains in optimal condition. Here are some tips for prolonging the life of the transfer box:

1. Regular Oil Checks and Changes: One of the most critical aspects of maintaining the transfer box is keeping the oil clean and at the correct level. Regularly check the oil level, and replace the oil according to the manufacturer's guidelines. Use only the recommended oil type to ensure proper lubrication and avoid premature wear.
   
2. Inspect Seals and Gaskets: Over time, seals and gaskets can deteriorate, leading to oil leaks. Inspect the seals and gaskets around the transfer box regularly and replace them at the first sign of wear. Keeping these components in good condition will help prevent oil loss and ensure proper lubrication.
   
3. Check for Proper Alignment: The transfer box must be properly aligned with the drivetrain to prevent undue stress on the components. Ensure that the transfer box is correctly mounted and aligned with the front and rear axles to reduce the risk of damage.
   
4. Ensure Proper Cooling: If the A35E is regularly subjected to heavy-duty operations or high temperatures, ensure that the transfer box is properly cooled. Overheating can lead to severe damage, so adding an oil cooler or ensuring adequate ventilation can help mitigate this issue.
   
5. Routine Inspections: Regularly inspect the transfer box for any signs of wear, damage, or leaks. Performing scheduled maintenance and catching problems early can save time and money on costly repairs later.
   

Conclusion
The Volvo A35E articulated hauler is a powerful and reliable machine, thanks in part to its transfer box, which plays a crucial role in distributing power to the axles and ensuring smooth operation. However, like any heavy-duty component, the transfer box can experience issues, including leaks, overheating, and mechanical failures. Regular maintenance, proper lubrication, and timely repairs are key to ensuring the transfer box continues to perform reliably.
By understanding the role of the transfer box and addressing common issues proactively, operators can keep the A35E in top shape, ensuring that it delivers the power and performance needed for the most demanding jobs.