Fan Belt for Gehl 4640 Skid Steer Loader

[MikePhua]

Introduction
The Gehl 4640 Skid Steer Loader has long been recognized as a versatile workhorse in construction, agriculture, and landscaping. Built during the 1990s by Gehl, a company whose roots trace back to 1859 in West Bend, Wisconsin, the 4640 was designed to offer compact power, agility, and reliability. Gehl began as a manufacturer of threshing machines, gradually expanding into construction equipment. By the 1970s, it had become a global brand, known for durable skid steers and loaders that could tackle the toughest jobs.
Equipped with the Deutz BF3M1011F diesel engine, the 4640 delivers up to 64 horsepower with a compact footprint. While many operators focus on engine performance or hydraulic systems, a small but critical component—the fan belt—often determines whether the machine operates reliably or experiences sudden failure. The fan belt drives essential accessories like the cooling fan and alternator. A worn or improperly tensioned belt can result in overheating, electrical issues, and premature wear of engine components.
Fan Belt Specifications
The fan belt in the Gehl 4640 is a V-type belt specifically engineered for the Deutz BF3M1011F engine. Key specifications include:

• Part Number: 132989
  
• Type: V-belt
  
• Width: 10 mm
  
• Length: 1050 mm
  
• Engine Compatibility: Deutz BF3M1011F
  

Using a belt that does not meet these specifications can lead to slippage, uneven wear, or damage to pulleys and bearings. While OEM belts guarantee fit and durability, high-quality aftermarket belts from reputable suppliers can be acceptable, provided dimensions and material standards match the original.
Signs of Fan Belt Wear
Operators often only notice fan belt issues after the machine starts exhibiting problems. Common symptoms include:

• Squealing or chirping noises during engine start or high load
  
• Overheating caused by a slipping cooling fan
  
• Dimming lights or electrical issues from alternator slip
  
• Fraying, cracks, glazing, or worn ribs on the belt
  

Ignoring these signs may result in engine damage, unplanned downtime, and expensive repairs. In real-world conditions, belts can wear out faster than manuals suggest, especially in dusty or high-temperature environments.
Maintenance and Replacement
Maintaining the fan belt is critical for consistent performance. Best practices include:

• Visual Inspection: Monthly checks for cracks, fraying, glazing, or uneven wear.
  
• Tension Check: Proper tension prevents slippage while avoiding excess stress on bearings. Standard deflection is 10–15 mm at midspan under moderate pressure.
  
• Pulley Cleaning: Keep pulleys free from oil, dirt, and debris to avoid premature wear.
  
• Replacement Schedule: Replace the belt if wear signs appear or during routine engine service, typically every 500–600 hours of operation.
  

Replacement Procedure
Replacing a fan belt on the Gehl 4640 is straightforward but requires attention to detail:

1. Shut down the engine and allow it to cool.
   
2. Open the engine compartment for access to the belt and tensioner pulley.
   
3. Relieve tension with the tensioner pulley or a pry bar.
   
4. Remove the old belt carefully, avoiding damage to surrounding components.
   
5. Install the new belt, routing it over all pulleys according to the engine diagram.
   
6. Adjust the tension to specification and confirm alignment.
   
7. Start the engine and check for smooth operation and proper tension.
   

Failing to follow these steps can result in belt slippage or early failure.
Preventive Measures
To extend the life of the fan belt and prevent downtime:

• Always keep a spare belt on-site for emergencies.
  
• Use high-quality lubricants and clean components to prevent contamination.
  
• Train operators to recognize early warning signs like squealing or dim lights.
  
• Inspect belts during every scheduled service, typically every 250 operating hours.
  
• In dusty or extreme environments, increase inspection frequency.
  

Case Study: Real-World Impact
A landscaping company in the Midwest had three Gehl 4640s that experienced overheating during peak summer months. Investigation revealed the fan belts were worn and tensioned incorrectly, causing inadequate cooling and intermittent electrical issues. After replacing all belts with OEM parts and instituting a bi-monthly inspection routine, the company reported a 25% increase in machine uptime within three months. Operators also noted smoother engine operation and more reliable electrical performance.
Production and Legacy
The Gehl 4640 series was produced in the 1990s, with thousands of units sold globally. Gehl’s attention to compact design and rugged durability helped it compete with Bobcat, Case, and other industry leaders. Today, many 4640s remain in service, testament to their engineering and proper maintenance practices.
Conclusion
While often overlooked, the fan belt plays a pivotal role in the reliability of the Gehl 4640 Skid Steer Loader. Proper inspection, correct tensioning, and timely replacement are essential to maintain engine efficiency, prevent overheating, and ensure operational reliability. Whether using OEM or verified aftermarket belts, prioritizing quality and adherence to specifications guarantees that your 4640 remains a dependable workhorse for years to come. Operators who follow these practices not only avoid costly repairs but also maximize uptime and productivity in the field.