JCB 185 Skid Steer Axle Troubleshooting and Component Insights

[MikePhua]

The JCB 185 and Its Compact Loader Heritage
The JCB 185 skid steer loader was introduced in the late 1990s as part of JCB’s push into the North American compact equipment market. With a rated operating capacity of approximately 1,850 lbs and a 56 hp diesel engine, the 185 was designed for versatility in construction, landscaping, and agricultural applications. JCB, founded in 1945 in Staffordshire, England, had already earned global recognition for its backhoe loaders and telescopic handlers. The 185 series extended that reputation into the skid steer segment, offering a side-entry cab, robust frame, and mechanical simplicity.
Unlike many competitors that used chain-driven axles, the JCB 185 employed a direct-drive axle system with planetary reduction hubs. This design improved torque transfer and reduced maintenance intervals, but it also introduced complexity in disassembly and troubleshooting.
Axle Assembly and Drive Configuration
The JCB 185 uses a hydrostatic drive system that powers each wheel independently through a hydraulic motor mounted directly to the axle hub. The axle assembly includes:

• Hydraulic drive motor
  
• Planetary gear reduction hub
  
• Axle shaft with splined engagement
  
• Bearing set and seal pack
  
• Brake disc and caliper (on some variants)
  

The planetary hub multiplies torque from the motor, allowing the machine to push through heavy material or climb steep grades. The axle shaft transmits this torque to the wheel, supported by tapered roller bearings and sealed against contamination.
In Alberta, a contractor used a JCB 185 for snow removal. After 2,000 hours, the left rear axle began leaking oil. Upon inspection, the outer seal had failed due to salt corrosion. Replacing the seal and flushing the hub restored full function.
Common Axle Issues and Diagnostic Clues
Axle problems in the JCB 185 often present as:

• Oil leakage from hub or motor flange
  
• Grinding noise during travel
  
• Wheel wobble or misalignment
  
• Loss of drive power on one side
  
• Brake drag or overheating
  

Root causes may include:

• Worn bearings or improper preload
  
• Damaged axle shaft splines
  
• Contaminated hydraulic fluid entering the motor
  
• Brake caliper misalignment or piston seizure
  
• Planetary gear wear or broken teeth
  

In Michigan, a fleet manager diagnosed intermittent drive loss on the right front wheel. The axle shaft had stripped splines due to improper torque during wheel installation. After replacing the shaft and torqueing to spec, the issue was resolved.
Disassembly Tips and Component Matching
When servicing the axle:

• Remove the wheel and hub cover
  
• Drain gear oil from the planetary hub
  
• Unbolt the hydraulic motor and inspect the flange
  
• Extract the axle shaft and inspect splines and bearing surfaces
  
• Replace seals and gaskets with OEM equivalents
  
• Refill with SAE 80W-90 gear oil or as specified
  

Recommended torque specs:

• Wheel lug nuts: 90–100 ft-lbs
  
• Motor flange bolts: 45–55 ft-lbs
  
• Planetary hub bolts: 60–70 ft-lbs
  

In Finland, a forestry crew rebuilt a JCB 185 axle using aftermarket bearings. The preload was miscalculated, leading to premature wear. After switching to OEM tapered rollers and using a dial gauge to set endplay, the axle ran smoothly for another season.
Brake System Integration and Adjustments
Some JCB 185 models include a mechanical disc brake integrated into the axle hub. This system uses:

• Steel brake disc mounted to the axle
  
• Hydraulic or mechanical caliper
  
• Return spring and adjustment screw
  
• Parking brake linkage or solenoid actuator
  

Brake issues may include:

• Constant drag due to seized caliper
  
• Uneven braking from misaligned pads
  
• Brake fluid leakage into hub
  
• Noisy operation during turns
  

Solutions:

• Clean and lubricate caliper pins
  
• Replace worn pads with high-friction material
  
• Inspect brake line routing and fittings
  
• Adjust brake screw to factory clearance spec
  

In Texas, a contractor added a heat shield to the rear brake caliper after noticing overheating during summer grading. This reduced fade and extended pad life.
Preventive Maintenance and Long-Term Reliability
To extend axle life:

• Change hub oil every 500 hours
  
• Inspect seals quarterly for leakage
  
• Torque wheel nuts after every tire change
  
• Flush hydraulic fluid annually
  
• Grease brake linkage monthly
  

A contractor in Shanghai added a magnetic drain plug to each planetary hub. This captured fine metal particles and allowed early detection of gear wear, preventing catastrophic failure.
Field Stories and Adaptations
In Alaska, a JCB 185 used for pipeline trenching developed axle noise in subzero temperatures. The technician switched to synthetic gear oil rated for –40°C and installed neoprene seals. The machine operated reliably through the winter.
In Poland, a demolition crew retrofitted their JCB 185 with reinforced axle guards to protect against debris impact. This reduced seal failures and improved uptime in rubble-heavy environments.
Conclusion
The axle system in the JCB 185 skid steer is a robust but precision-engineered component that demands careful maintenance and accurate diagnostics. From planetary gear inspection to brake alignment, each part plays a role in delivering torque, stability, and control. In compact loaders, the axle isn’t just a connection—it’s the backbone of mobility.