National 221510 Transfer Case Shift Shaft Seal

Transfer Case Shift Shaft Seal for Toyota and Lexus 4WD

National 221510 is a metric transfer case shift shaft seal built for applications that need a precise seal at the shift shaft. With a 15.000 mm shaft size, 25.250 mm outside diameter, and 6.000 mm width, it is sized for select Toyota and Lexus 4WD transfer cases that use Aisin units.

National has supplied sealing solutions for more than 75 years, and this oil seal reflects that focus on fit, material selection, and durability. The polyacrylate sealing material is suited for transfer case sealing needs where consistent contact and dimensional accuracy matter.

• Transfer case shift shaft seal for select Toyota and Lexus 4WD applications
• National part number 221510
• Metric dimensions: 15.000 mm shaft, 25.250 mm outside diameter, 6.000 mm width
• Polyacrylate sealing material for transfer case sealing service
• Oil seal design for the transfer case shift shaft area
• Cross-reference: Monroe Shocks & Struts 5803

Detailed Product Information

This National 221510 transfer case shift shaft seal is engineered for vehicles using Aisin transfer cases, including many Toyota 4Runner, Tacoma, Tundra, FJ Cruiser, Sequoia, Pickup, T100, and Lexus GX models. It also applies to select Corolla, Camry, Celica, Tercel, Paseo, MR2, and Geo/Chevrolet Prizm and Nova applications listed in the fitment data. The seal’s 0.591 inch inside diameter, 0.994 inch outside diameter, and 0.236 inch thickness help support a proper sealing interface at the shaft and housing bore.

Use National 221510 when servicing a leaking or worn transfer case shift shaft seal on vehicles such as the Toyota 4Runner, Toyota Tacoma, or Lexus GX470/GX460 with the specified Aisin transfer case configuration. The part number 221510 is a direct reference for this seal style, and the metric sizing helps confirm application match before installation.

Common Problems This Seal Addresses

• Transfer case fluid seepage at the shift shaft
• Oil residue around the transfer case housing
• Seal wear from age, heat, and shaft movement
• Loss of sealing integrity during transfer case service
• Contamination entering the transfer case through a worn shaft seal

Installation Notes and Tips

Verify the transfer case model, shaft diameter, housing bore, and vehicle configuration before installation. Confirm the Aisin transfer case type and 2-speed setup listed in the fitment data for your Toyota or Lexus application. Inspect the shaft surface for grooves or damage, and clean the bore thoroughly so the new seal seats evenly.

For best results, install the seal squarely and avoid damaging the sealing lip during assembly. Match the seal dimensions to the original part before final installation on Toyota 4Runner, Tacoma, Tundra, FJ Cruiser, and Lexus GX applications.

Quality Assurance

National is a long-established sealing brand known for producing replacement oil seals and related sealing components for automotive service. Part number 221510 is built to the listed metric dimensions and material specification for the applications shown.