National Wheel Seal 370001A for Isuzu, Chevrolet & GMC Trucks — Unitized Oil-Bath, Spring-Loaded Lip

The National 370001A Wheel Seal is a rugged, unitized oil-bath seal engineered to stop axle leaks and protect wheel bearings on select Isuzu, Chevrolet and GMC trucks.

Built by a brand with over seven decades in sealing technology, this wheel seal combines a spring-loaded nitrile lip, abrasion protection, and patented Sure-Lock ribs to offer reliable contact sealing over a wide temperature range. Its unitized design improves structural strength and simplifies installation compared with multi-piece seals, while materials and construction are chosen to withstand heavy-duty driving conditions.

What vehicles is the 370001A compatible with?

This seal fits a range of medium- and heavy-duty Isuzu, Chevrolet and GMC models from the late 1990s through the 2010s. Always confirm fitment with your vehicle details before ordering to ensure correct application.

• Isuzu: 2005–2011 FVR, 2004–2011 FXR, 2005–2007 HTR, 2005–2008 HVR
• Chevrolet: 1997–2009 T6500/T7500; 2003–2009 C6500/C7500 Kodiak
• GMC: 2003–2009 C6500 TopKick
• Use the seller’s fitment tool (enter year, make, model, engine and trim) and read any fitment notes shown.

How does the construction improve durability and installation?

The seal uses a unitized assembly that strengthens the component and protects the primary sealing lip during installation. A spring-loaded main lip maintains steady contact with the shaft while the abrasion-resistant nitrile body resists wear from contaminants and heat.

• Unitized body for increased structural integrity and simpler install
• Spring-loaded main lip for constant shaft contact and leak prevention
• Abrasion-protected nitrile to resist scoring and surface wear
• Patented Sure-Lock ribs on ID/OD to reduce bore leakage and hold position

What operating conditions can this wheel seal handle?

This design tolerates a wide range of temperatures and typical heavy-duty vehicle environments without rapid degradation. Its oil-bath orientation and material choices provide dependable sealing across cold starts and hot-running conditions.

• Temperature rating: -40°F to 225°F (-40°C to 107°C)
• Designed for oil-bath wheel hubs and axle applications
• Resists abrasion, shaft interference and contamination ingress
• Recommended where continuous oil contact and point-contact sealing are required

What should I check before buying and installing this part?

Verify the exact vehicle fitment and read any fitment notes provided by the seller or fitment tool. Inspect the hub bore and shaft for damage, and replace worn bearings or mating hardware to ensure a proper seal life.

• Confirm fit via the online “Confirmed Fit” tool using full vehicle specs
• Check for fitment notes (look for the blue “i” indicator before purchase)
• Clean and inspect mating surfaces; replace damaged hubs or shafts
• Follow proper installation technique to avoid nicking the sealing lip

Who is this for? The National 370001A is aimed at professional technicians, fleet maintenance crews and DIY mechanics servicing medium- and heavy-duty Isuzu, Chevrolet and GMC trucks that require a durable, oil-bath wheel seal. Choose this part when you need a robust, ready-to-install seal with proven sealing features and broad compatibility—but always confirm vehicle fitment and prepare the hub and shaft correctly for best results.