Frequently Asked Questions

1. Why is the bearing temperature too high?
High bearing temperatures can result from overloading, insufficient or incorrect lubrication, bearing wear, or misalignment. Regular inspections and proper lubrication are essential to prevent these issues.

At Bonfiglioli, our gearboxes feature correct bearing selection, precision alignment during installation, and use of certified lubricants—all designed to help prevent overheating and significantly extend bearing life.

2. What causes the gearbox operating temperature to rise excessively?
Excessive gearbox operating temperature can result from overloading, poor ventilation, low or contaminated oil, or worn internal components. Regular maintenance and proper functioning of cooling and lubrication systems are crucial to prevent overheating and safeguard the gearbox.

Bonfiglioli gearboxes come factory-filled—unless otherwise specified—with high-quality synthetic or semi-synthetic oils sourced from reputable manufacturers. The filling process takes place in a controlled environment to avoid contamination, ensuring longer service intervals and reliable, efficient operation.

3. What does abnormal running noise from the gearbox indicate?
Unusual noises from a gearbox often signal underlying problems such as internal wear, misalignment, gear damage, or bearing failure. Ignoring these warning signs can lead to severe damage and costly downtime, so prompt attention is essential.

At Bonfiglioli, we specialize in identifying and resolving gearbox issues through comprehensive vibration and noise diagnostics. Our state-of-the-art diagnostic tools accurately pinpoint the cause of abnormal sounds, enabling precise maintenance and repairs. Additionally, we supply genuine OEM replacement components engineered to the highest standards, ensuring seamless compatibility and long-lasting performance.

With Bonfiglioli’s expertise and quality solutions, you can trust your gearbox to operate smoothly, efficiently, and reliably.

4. Why is there abnormal noise at the gear unit mounting?
Abnormal noise at the gear unit mounting can be caused by loose bolts, misaligned mounts, or vibrations transmitted from connected equipment. It’s important to secure all fixings tightly and verify proper alignment during installation and maintenance.

Bonfiglioli gear units help minimize these issues through their robust design and use of precision-engineered mounting systems. Our installation kits include anti-vibration components and come with clear torque guidelines, ensuring a secure, vibration-resistant fit that reduces noise and extends the life of both the gearbox and connected machinery.

5. What causes oil leaks in a gearbox?
Oil leaks can be caused by worn seals, overfilled units, damaged housings, or excessive pressure or temperature. Prompt repair is critical to prevent oil loss and avoid serious component damage.

Bonfiglioli gearboxes are designed with advanced sealing technologies that provide superior protection against leaks. We use high-quality, durable seals engineered to withstand pressure and temperature variations. Additionally, our gearboxes undergo rigorous quality control and precision manufacturing to ensure perfect fit and integrity of all sealing surfaces. We also offer proactive seal replacement programs that detect and address potential leak issues before they impact performance, ensuring reliable operation and longer gearbox life.

6. Why does the gear unit not run or run with difficulty?
Common reasons include seized components, inadequate lubrication, incorrect assembly, or electrical motor issues. A full inspection is required to diagnose the cause.

Our expert technicians provide comprehensive diagnostic services using advanced tools to quickly identify the problem. We ensure correct installation and precise assembly to prevent operational issues. Additionally, we supply genuine Bonfiglioli parts engineered for durability and optimal performance, helping restore your gear unit to full, reliable operation. With our support, you can minimize downtime and extend the service life of your equipment.

7. How often should a gearbox be serviced?
Routine inspections should be performed every 6–12 months, with oil replacement typically needed every 2,500–5,000 operating hours, depending on load, environment, and lubricant condition. Always adhere to the manufacturer’s guidelines for precise service intervals.

Bonfiglioli offers customized annual maintenance contracts featuring scheduled inspections, oil analysis, and preventive servicing tailored to your gearbox’s specific operating conditions. This proactive approach ensures optimal performance, minimizes unplanned downtime, and extends the lifespan of your equipment.

8. What are common signs of gearbox failure?
Indicators include excessive noise, vibration, overheating, oil leaks, reduced performance, or irregular shaft movement. Early detection can prevent major breakdowns.

Bonfiglioli gearboxes are designed and manufactured with high-quality materials and precision engineering to ensure durability and reliable operation under demanding conditions. Our advanced condition monitoring systems continuously track gearbox health, detecting early warning signs such as temperature spikes, vibration irregularities, and lubrication issues. This proactive monitoring enables timely maintenance and corrective actions, significantly reducing the risk of unexpected failures, maximizing uptime, and extending the service life of your equipment.

9. What type of lubricant should be used in a gearbox?
Always use the manufacturer-recommended lubricant, including the correct viscosity grade and formulation. The wrong oil can lead to inadequate lubrication, overheating, and accelerated wear of gears and bearings—ultimately causing premature failure.

We supply genuine, factory-approved lubricants specifically engineered for Bonfiglioli gearboxes. These lubricants ensure optimal performance, extended service life, and full compatibility with internal components—helping you maintain reliability under all operating conditions.

10. How do I check the gearbox oil level?
Use the oil sight glass or dipstick while the gearbox is at rest on a level surface. Ensure the oil level aligns with the designated fill mark specified in the user manual. Accurate oil level checks are essential to maintain proper lubrication and prevent damage.

Our gear units come equipped with user-friendly oil indicators for quick and reliable monitoring. These indicators not only display the oil level but, in some models, also signal when oil changes or top-ups are needed. Our detailed manuals provide clear guidance to help you perform checks confidently and correctly.

11. What causes gearbox overheating?
Common causes include overloading, inadequate or degraded lubrication, blocked or inefficient cooling systems, and excessive mechanical wear. Overheating can accelerate component failure, so it’s vital to ensure proper operating conditions and perform regular maintenance.

Bonfiglioli gearboxes are engineered with optimized thermal management features, including efficient cooling designs and the use of high-performance synthetic or semi-synthetic lubricants that maintain stability under high temperatures. Our gearboxes undergo rigorous quality control and are factory-filled in controlled environments to prevent contamination and ensure optimal lubrication from the start. Additionally, we offer comprehensive thermal assessments and tailored recommendations—such as cooling system upgrades and lubrication strategies—to maintain ideal operating temperatures, protecting your gearbox from thermal stress and ensuring reliable, long-lasting performance.

12. Can I clean my gearbox using water or pressure washers?
No. High-pressure water or direct washing can compromise seal integrity and lead to water ingress, resulting in internal corrosion and premature failure. Gearboxes are not designed to withstand moisture intrusion.

We recommend dry-cleaning methods or the use of approved, non-corrosive cleaning agents. Our service guidelines include detailed cleaning protocols to ensure safe and effective maintenance without risking damage to internal components.

13. When should the gearbox oil be replaced?
Typically, after the first 500 hours (break-in period), then every 2,500–5,000 hours or annually, depending on load, operating environment, and oil condition.

We offer comprehensive oil analysis and replacement services tailored to your actual operating conditions. Our experts monitor oil quality to determine the optimal replacement interval, helping you avoid unnecessary changes, reduce wear, and maximize gearbox efficiency and service life—all using genuine Bonfiglioli-approved lubricants.

14. How can I reduce vibration in a gearbox?
Check for proper shaft alignment, balance rotating parts, ensure tight mountings, and inspect for worn gears or bearings. Vibration analysis can help detect early issues.

Bonfiglioli gearboxes feature high-precision components and tight tolerances for smooth, balanced operation. Our sturdy design reduces internal imbalances and mechanical stress. We also offer vibration analysis, alignment corrections, and balancing solutions to prevent excessive vibration, minimize wear, and ensure reliable, long-lasting performance.

15. Is it safe to operate a gearbox with minor oil leakage?
No. Even small leaks can lead to oil starvation and severe damage. Address all leaks promptly to maintain performance and avoid costly repairs.

Our gearboxes feature advanced sealing technologies and are built with high-quality materials to ensure superior sealing integrity. Precision manufacturing guarantees perfectly fitting components that resist wear and pressure, minimizing the risk of leaks. Combined with expert installation and maintenance using genuine Bonfiglioli parts, this approach effectively protects your gearbox from oil leakage—maximizing uptime and extending service life.