Resolving Belt Squeal on the Bobcat 773G Series Requires Proper Tensioner Adjustment and Drive System Inspection

[MikePhua]

Bobcat 773G Series Background
The Bobcat 773G Series skid steer loader was introduced in the early 2000s as part of Bobcat’s G-series lineup, which emphasized improved operator comfort, hydraulic performance, and simplified maintenance. Bobcat Company, founded in 1947 in North Dakota, has been a leader in compact equipment, and the 773G was designed to serve contractors, landscapers, and utility crews with a mid-frame machine offering vertical lift geometry.
Powered by a 46-horsepower Kubota V2203 diesel engine, the 773G features a hydrostatic drive system, dual-path hydraulics, and a belt-driven fan and alternator assembly. Its operating weight is approximately 5,800 pounds, with a rated operating capacity of 1,750 pounds. The machine’s reliability and ease of service made it a popular choice, with thousands sold across North America.
Identifying the Source of Belt Squeal
A common issue reported by operators is a persistent squealing noise, often mistaken for a worn drive belt. In many cases, the belt is replaced, but the noise continues. This leads to confusion and concern about potential hydraulic or drivetrain damage.
Key observations include:

• Squeal occurs primarily in forward motion
  
• Noise disappears when reversing
  
• Drive belt appears tight and recently replaced
  
• No signs of creep when in neutral
  

These symptoms suggest that the issue is not with the drive belt itself, but rather with the fan belt tensioner or idler bearing.
Fan Belt Tensioner and Spring Mechanism
The fan belt on the 773G is tensioned by a spring-loaded arm that pivots to maintain proper belt tension. If the pivot bolt binds or the spring loses tension, the belt may slip under load, causing a high-pitched squeal. This is especially noticeable when the machine moves forward, as the fan load increases due to airflow resistance.
To inspect and adjust:

• Check the tensioner arm for free movement
  
• Lubricate the pivot bolt and inspect for corrosion
  
• Verify spring integrity and replace if fatigued
  
• Adjust the tensioner to the recommended position—typically between 2 and 3 o’clock, avoiding full compression
  

In one case, an operator temporarily resolved the issue by securing the tensioner with a bungee cord, which increased tension and eliminated the squeal. While not a permanent fix, it confirmed the tensioner as the root cause.
Drive Belt and Idler Bearing Inspection
Although the drive belt was replaced, it’s important to verify:

• Belt alignment across pulleys
  
• Proper tension using a torque bar (not over-tightened)
  
• Condition of the idler bearing—listen for grinding or resistance
  
• Spring tensioner position per manual guidelines
  

Over-tightening the drive belt can damage bearings and reduce belt life. The tensioner should be allowed to float within its designed range.
Hydraulic System Considerations
Some operators worry that the squeal may indicate hydraulic overload or internal damage. However, if the machine does not creep in neutral and hydraulic functions remain responsive, the issue is likely mechanical. Still, it’s wise to:

• Check hydraulic fluid level and condition
  
• Inspect for leaks around pumps and motors
  
• Monitor system pressure during operation
  

Conclusion
Belt squeal on the Bobcat 773G Series is most often caused by improper fan belt tension due to a binding tensioner or weak spring. While the drive belt may appear to be the culprit, the noise pattern—especially its disappearance in reverse—points to fan load dynamics. By inspecting the tensioner assembly, verifying spring action, and ensuring proper belt alignment, operators can resolve the issue and prevent further wear. For long-term reliability, replacing worn tensioner components and maintaining clean pivot points is essential.