Fixing an Axle Seal Leak on a Bobcat A300: Diagnosis and Repair Insights

[MikePhua]

First Signs: Oil Under the Wheel
When fat, dark fluid drips under the rear wheel of a Bobcat A300 with minimal hours on the clock, your first thought might be a hydraulic leak—but often, the culprit is simpler: a failing axle seal.
Key Technical Terms

• Axle seal: A small gasket located between the wheel hub and axle to retain chain case oil and prevent leakage.
  
• Chain case: The gear housing that sends power to the wheels; its lubricant may seep past worn seals.
  
• Wheel hub removal: The process of taking off the wheel so the hub and seal can be accessed.
  
• All‑wheel‑steer loader: A machine where all wheels steer, meaning axle and hub assemblies are more complex and may have multiple seals.
  

Practical Repair Techniques
Professional technicians and experienced users suggest the following steps:

• Remove the wheel and hub by unbolting retaining nuts or bolts.
  
• Access the axle seal and gently pry it out—drilling tiny holes and using screw heads as leverage is a classic trick for seal extraction.
  
• Replace the seal with a correct part (genuine or verified aftermarket) sized to fit the Bobcat model.
  
• Reassemble in reverse—securely torque the hub, then reinstall the wheel.
  

For example, one seasoned operator shared that the leak channel was traced directly to the chain case area and required hub removal to reach the failed axle seal—even though the machine had low usage hours. Another expert noted that all-wheel‑steer configurations, like the A300, often contain both input and output seals within the hub assembly, multiplying potential leak points.
Real-World Repair Story
One owner, confronted with expensive dealer quotes, took a DIY route after consulting resources. By unloading the rear wheel, gently removing the hub, and extracting the old seal, he replaced it with a fresh cartridge-style seal. The leak stopped immediately, saving significant costs and downtime.
Step‑by‑Step Checklist

• Park safely on level ground and secure the machine.
  
• Remove wheel and hub carefully.
  
• Extract the failing axle seal—drilling small holes and prying is acceptable with care.
  
• Identify and install the appropriate replacement seal.
  
• Secure the hub and re-mount the wheel using proper torque.
  
• Test for leaks and fluid retention after operation.
  

Maintenance Takeaways

• A severe rear leakage from a seemingly new machine often indicates a seal failure—not necessarily wear from mileage.
  
• All-wheel-steer systems use more complex hub assemblies, increasing the number of seals that can fail.
  
• DIY approaches—with patience and correct parts—can resolve this issue without expensive dealership service.
  

Need torque specs, seal sourcing tips, or hub disassembly visuals? Happy to dig in further!