National wheel seal 370025A for Clark & Rockwell‑Standard FWRW — Dynamic Edge, unitized nitrile

National 370025A is a heavy-duty, unitized oil-bath wheel seal engineered to protect axle shafts and bores on Clark and Rockwell-Standard FWRW applications.

Designed by National — a sealing specialist with more than 75 years in the industry — this Dynamic Edge Red 37 Series seal provides durable point-contact sealing for oil-bath wheel ends. Its unitized construction, abrasion-resistant nitrile, and patented SURE-LOCK ribs combine to reduce leaks, resist wear, and simplify installation so you can return the vehicle to service with confidence.

How does the 370025A keep oil in and contaminants out?

The seal uses a spring-loaded main lip that maintains positive contact with the shaft while minimizing interference. The Dynamic Edge design creates a focused point seal for better retention of lubricant in oil-bath hubs and improved exclusion of dirt and moisture.

• Spring-loaded main lip for sustained contact and sealing force
• Abrasion-resistant nitrile compound that stands up to shaft wear
• SURE-LOCK ribs on the I.D. and O.D. to inhibit shaft leaks and protect bores
• Temperature-rated -40°F to 225°F / -40°C to 107°C for common operating ranges

Will this seal fit my Clark or Rockwell-Standard FWRW axle assembly?

Compatibility depends on the exact axle design and dimensions. National provides fit guidance, and online vehicle-fit tools can confirm compatibility when you supply year, make, model and axle details.

• Engineered specifically for Clark and Rockwell-Standard FWRW wheel ends
• Check vehicle-fit information and qualifier notes before ordering
• If an online tool shows an information icon, review the additional notes for fit details

What materials and construction features improve durability and installation?

Unitized construction gives the seal greater structural integrity and protects the main lip during handling and installation. The rubber compounds and design details reduce installation errors and extend service life in oil-bath applications.

• Unitized assembly simplifies installation and protects sealing elements
• Nitrile compound resists abrasion and typical service contaminants
• Patented SURE-LOCK ribs guard bore surfaces and reduce migration
• Dynamic Edge geometry promotes point contact sealing for long-term performance

How should I handle installation and service expectations?

Prepare the shaft and bore by cleaning and inspecting for wear or damage; replace or repair any compromised surfaces for best sealing performance. Install the unitized seal without distorting the lip and verify proper seating to prevent premature leaks.

• Clean mating surfaces and check shafts for scoring or grooves
• Use correct seating tools to avoid lip deformation during installation
• Verify axial and radial fit per vehicle or axle specifications
• Monitor the seal at first service interval for signs of seepage or wear

Who is this for: The National 370025A is intended for professional mechanics, fleet technicians, and experienced DIYers working on Clark or Rockwell-Standard FWRW wheel ends that use oil-bath lubrication. It’s suited for vehicles and equipment that require a robust, unitized wheel seal with proven design features — especially where durability, straightforward installation, and reliable leak control are priorities.