Removing the Crankshaft Pulley on a Massey Ferguson 50HX

[MikePhua]

The MF 50HX and Its Mechanical Lineage
The Massey Ferguson 50HX is a backhoe loader developed during the 1980s as part of MF’s industrial equipment range. Built for durability and versatility, the 50HX was widely used in construction, agriculture, and municipal work across Europe and Commonwealth markets. It featured a Perkins diesel engine, typically the 4.236 or 4.248 series, known for their reliability and ease of service.
Massey Ferguson, founded in 1953 through the merger of Massey-Harris and Ferguson, became one of the most recognized names in agricultural and industrial machinery. The 50HX was part of a broader push into the backhoe loader segment, competing with JCB and Ford in the compact utility market. Thousands of units were sold, and many remain in service today, especially in rural fleets and restoration circles.
Purpose and Challenges of Crankshaft Pulley Removal
The crankshaft pulley is mounted at the front of the engine and serves as the drive point for belts powering the alternator, water pump, and hydraulic pump. It is typically press-fitted or keyed onto the crankshaft nose and secured with a central bolt. Removal is necessary for:

• Timing gear access
  
• Front oil seal replacement
  
• Crankshaft inspection
  
• Pulley replacement due to wear or damage
  

Challenges include:

• Rust and corrosion bonding the pulley to the shaft
  
• Limited access in the engine bay
  
• Risk of damaging the pulley or crankshaft threads
  
• High torque required to loosen the retaining bolt
  

Terminology Note: “Press-fit” refers to a tight mechanical fit requiring force to separate components. “Keyed shaft” uses a metal key to prevent rotational slippage between the pulley and crankshaft.
In 2022, a restorer in Yorkshire attempted to remove the pulley on his MF 50HX and snapped a generic puller. He later used a custom-fabricated plate puller and heat application to complete the job without damage.
Recommended Tools and Preparation
Before removal:

• Disconnect battery and remove fan belts
  
• Drain coolant if water pump is belt-driven
  
• Remove radiator or shroud for access if needed
  
• Clean pulley face and bolt area with penetrating oil
  

Tools required:

• Heavy-duty three-jaw or plate-style puller rated for industrial use
  
• Breaker bar or impact wrench for central bolt
  
• Heat gun or propane torch for thermal expansion
  
• Anti-seize compound for reinstallation
  
• Torque wrench for final assembly
  

Specifications:

• Central bolt torque: ~200–250 Nm depending on engine model
  
• Pulley bore diameter: ~2 inches
  
• Keyway width: ~6 mm
  
• Thread pitch: typically UNF or metric fine
  

Step-by-Step Removal Strategy

1. Soak the pulley hub and bolt with penetrating oil overnight
   
2. Use a breaker bar to loosen the central bolt while locking the flywheel or using a crankshaft holding tool
   
3. Remove the bolt and washer
   
4. Mount the puller evenly across the pulley face, ensuring centered pressure
   
5. Apply gradual force with the puller while tapping the pulley with a brass hammer
   
6. If stuck, apply heat to the pulley hub (not the crankshaft) to expand the metal
   
7. Once removed, inspect the keyway and crankshaft nose for wear or scoring
   

Safety tips:

• Wear eye protection during puller use
  
• Avoid excessive heat that could damage seals or bearings
  
• Do not pry with screwdrivers or chisels—risk of pulley fracture
  

A technician in New Zealand used a hydraulic puller with a 10-ton rating to remove a seized pulley from a 4.236 engine. The job took 45 minutes and revealed a worn front seal, which was replaced along with the pulley.
Reinstallation and Preventive Measures
To reinstall:

• Clean crankshaft nose and pulley bore
  
• Apply anti-seize compound to mating surfaces
  
• Align keyway and insert key securely
  
• Torque central bolt to spec using thread locker
  
• Reinstall belts and check alignment
  

Preventive tips:

• Inspect belts for wear and replace if cracked or glazed
  
• Check pulley grooves for deformation
  
• Replace front seal if oil is present behind pulley
  
• Use rust inhibitor on exposed metal surfaces
  

Some operators retrofit harmonic balancer pulleys for smoother engine operation. Others install belt tensioners to reduce wear on accessories.
Conclusion
Removing the crankshaft pulley on a Massey Ferguson 50HX is a task that demands patience, proper tooling, and mechanical awareness. Whether replacing a front seal or restoring a vintage Perkins engine, the key is controlled force and clean technique. With the right preparation and a steady hand, even the most stubborn pulley can be removed without damage—preserving the legacy of a machine built to last. In the world of classic backhoes, every bolt tells a story, and the crankshaft pulley is no exception.