Axle Seal Replacement and Bearing Service on the Case 90XT Skid Steer

[MikePhua]

The 90XT and Case’s Skid Steer Evolution
The Case 90XT skid steer loader, introduced in the early 2000s, was part of Case Construction’s XT series—a lineup that emphasized power, hydraulic versatility, and service accessibility. With a rated operating capacity of approximately 2,800 lbs and a gross engine output near 90 hp, the 90XT was designed for demanding applications in construction, agriculture, and demolition. Case, founded in 1842, had by then become a global leader in compact equipment, and the XT series helped solidify its reputation for rugged, easily serviceable machines.
The 90XT features a chain-driven axle system housed within a sealed mainframe. Each axle passes through a bearing assembly and seal interface to prevent gear oil leakage and contamination. Over time, these seals degrade due to heat, vibration, and wear—leading to oil seepage and bearing damage if not addressed promptly.
Terminology Annotation
- Axle Housing: The structural casing that supports the axle shaft and encloses the bearing and seal assembly.
- Sprocket Retaining Nut: A large nut accessed through the mainframe that secures the chain sprocket to the axle shaft.
- Bearing Cup and Cone: The two components of a tapered roller bearing; the cup is the outer race, and the cone includes the rollers and inner race.
- O-Ring Seal: A circular elastomeric gasket used to seal the interface between the axle housing and the mainframe.
Accessing and Removing the Axle Assembly
To replace the axle seal on the 90XT, the first step is to access the sprocket retaining nut. This is done by removing a 3-inch plastic plug located on the inside of the mainframe, beneath the floorboard. Once exposed, the nut can be removed using a socket and breaker bar. With the sprocket detached, the axle housing can be pulled free from the mainframe.
This process is relatively straightforward, but care must be taken to avoid damaging the chain or misaligning the sprocket teeth. It’s recommended to mark the sprocket orientation before removal to ensure proper reinstallation.
A Story from the Texas Panhandle
In Amarillo, a rancher using a Case 90XT for fencing and feed work noticed gear oil pooling beneath the front axle. Upon inspection, he found the seal had failed and the bearings were dry. After locating the plastic plug and removing the sprocket nut, he was able to press out the worn bearings and seals. He sourced a complete rebuild kit from a regional dealer, which included upgraded seals and new bearing cups. The repair took a full afternoon, but the loader was back in service the next morning—running smoother and quieter than it had in months.
Recommended Parts and Service Kit
Case offers a comprehensive axle service kit for the 90XT that typically includes:

• Inner and outer axle seals
  
• Bearing cups and cones
  
• Sprocket retaining nut
  
• O-ring for housing-to-frame seal
  
• Grease and installation instructions
  

While some components like bearings and races can be sourced from industrial suppliers, the upgraded seal design is proprietary and best obtained from a Case dealer. The newer seal is thicker and more resistant to heat and abrasion than the original.
Service Tips and Preventative Measures
To ensure long-term reliability:

• Repack bearings every 1,000 to 1,500 operating hours
  
• Inspect all four hubs during seal replacement to catch early wear
  
• Use high-quality gear oil rated for extreme pressure and temperature
  
• Install threaded plugs in the top and bottom of the hub to allow oil fill and drain
  
• Run bearings in heavy gear oil for improved lubrication and reduced maintenance
  
• Torque sprocket nut to factory spec and use thread locker to prevent loosening
  

For machines operating in dusty or wet environments, consider adding external hub guards to reduce contamination.
Conclusion
Replacing the axle seal on a Case 90XT skid steer is a manageable task that restores drivetrain integrity and prevents costly bearing failure. With proper tools, a service kit, and attention to detail, operators can complete the job in a single day and extend the life of their machine. The 90XT’s design allows for direct access to critical components, making it a favorite among owners who value maintainability as much as performance. In the world of compact loaders, durability begins at the axle—and the Case 90XT delivers.