Replacing Rear Axle Seals on a Bobcat 763 Skid Steer

[MikePhua]

Quick answer
Replacing rear axle seals on a Bobcat 763 is a manageable task for a skilled DIY mechanic, but often signals deeper wear in the axle bearings. If tackled at home, expect moderate labor and parts cost; if outsourced to a dealer, the repair may exceed the machine’s value.
Bobcat 763 overview and drivetrain design
The Bobcat 763 skid steer loader was introduced in the mid-1990s as part of Bobcat’s 700-series lineup. It features a 46-horsepower Kubota diesel engine, hydrostatic drive, and chaincase-style final drives. The rear axle shafts pass through sealed bearings housed in the chaincase, with seals preventing hydraulic oil from leaking into the wheel hubs.
The 763 was widely adopted for landscaping, construction, and agricultural use due to its compact footprint and reliable performance. Tens of thousands were sold globally, and many remain in service today.
Symptoms and implications of seal failure
Rear axle seal failure typically presents as:

• Oil leakage around the wheel hub
  
• Contaminated chaincase fluid
  
• Increased bearing noise or play
  
• Reduced drive efficiency
  

While seals can degrade from age or heat, they often fail due to worn bearings. Loose bearings allow shaft wobble, which damages the seal lip and leads to leakage. Replacing the seal without addressing bearing wear is a temporary fix.
Disassembly and replacement procedure
To replace the rear axle seals:

• Remove the wheel and hub assembly
  
• Drain the chaincase fluid
  
• Access the inner bolt and sprocket inside the chaincase
  
• Pull the axle shaft outward
  
• Remove the old seal using a pry tool
  
• Inspect and replace bearings and races if worn
  
• Install the new seal using a depth-specific driver (Bobcat recommends a proprietary seal driver)
  
• Reassemble and refill the chaincase
  

This process requires basic tools, mechanical skill, and attention to cleanliness. The proprietary seal driver ensures correct depth and alignment, but many technicians fabricate their own or use a universal driver with care.
Cost considerations and repair strategy
Parts cost for seals and bearings is modest—typically under $200. Labor time ranges from 4 to 6 hours for both sides. However, dealer repairs may exceed $1,500 due to labor rates and markup. For machines valued under $10,000, such as a used 763 priced at $7,500, dealer repair may not be economically viable.
DIY repair is feasible and often preferred. One operator joked that if the job turned out too painful, he’d “set the thing on fire and toast marshmallows over it”—a humorous nod to the frustration of unexpected repairs.
Used market alternatives and evaluation tips
When shopping for a used skid steer, consider:

• Check for axle seal leaks and chaincase fluid condition
  
• Inspect wheel hub play and listen for bearing noise
  
• Ask about prior seal or bearing replacements
  
• Compare with other models like John Deere 250 or Bobcat 190
  
• Evaluate total hours and attachment compatibility
  

A Deere CT332 with 11,000 hours priced at $25,000 may offer better long-term value than a cheaper unit needing drivetrain work. However, for pairing with an excavator and light-duty use, a well-maintained 763 under $15,000 remains a practical choice.
Conclusion
Rear axle seal replacement on a Bobcat 763 is a moderately challenging but achievable repair for experienced mechanics. It often reveals deeper bearing wear, so a thorough inspection is essential. With the right tools and patience, the job can be done at home—saving money and extending the life of a reliable machine.