National 223802 Transfer Case Output Shaft Seal - Rear

Transfer Case Output Shaft Seal for BMW and Suzuki

National 223802 is a metric transfer case output shaft seal built for applications that need controlled oil retention at the output shaft. It uses a polyacrylate sealing material, a clockwise-spiral lip design, and Redicoat treatment to support consistent sealing performance in drivetrain service.

Compatible With BMW 325Ci, 330Ci, X3, X5, 320i, 325i, 325xi, 330i, 330xi, 525i, 530i, Z4, Z3, 323Ci, 323i, 328Ci, 328i, 528i, 323is, 328is, 325is, 525iT, 325iX, 528e, 325e, 325es, and 524td applications, as well as Suzuki Samurai rear transfer case applications with Suzuki TS45 Transfer Case, Part Time 4WD, 2 Speed. This part cross-references Four Seasons 66905 for the same application.

• Part number: 223802
• Transfer case output shaft seal / oil seal
• Polyacrylate sealing material for drivetrain sealing service
• Clockwise-spiral lip design
• Metric dimensions: 38.000 mm shaft, 50.220 mm outside diameter, 8.000 mm width
• Redicoat treated
• National 220000 series, Type 32

Detailed Product Information

National 223802 is engineered as a transfer case output shaft seal for vehicles that require a precise metric fit. Key dimensions include a 1.496 inch (38.000 mm) inside diameter, 1.977 inch (50.220 mm) outside diameter, and 0.315 inch (8.000 mm) thickness, with a 1.969 inch (50.000 mm) housing bore specification. The polyacrylate sealing material and clockwise-spiral lip design are selected for sealing at rotating shafts where oil control is critical. National has supplied sealing solutions for more than 75 years, and this seal reflects that focus on drivetrain sealing applications.

What It Helps Address

• Transfer case oil seepage at the output shaft
• Fluid loss around the shaft-to-housing sealing surface
• Contamination entering the transfer case through a worn seal
• Noise or driveline issues caused by low lubricant level
• Service replacement for aging BMW and Suzuki transfer case seals

Installation Notes and Tips

Verify shaft diameter, housing bore, and seal width before installation. Inspect the output shaft and bore for wear, scoring, or corrosion, since surface damage can shorten seal life. Clean the sealing area thoroughly and install the seal squarely to avoid lip distortion. Confirm the transfer case application and position before ordering, especially on BMW and Suzuki Samurai drivetrain service.

Quality Assurance

National designs sealing products for modern vehicle service and drivetrain repair. Part number 223802 is part of the National 220000 series and uses a metric construction with Redicoat treatment for sealing support in transfer case applications.