National 710173

National 710173 is a directional radial shaft seal used primarily as the front crankshaft seal in the timing cover of selected Buick 350 CID / 5.7 L V8 engines. Its clockwise hydrodynamic lip pattern helps return oil toward the inside of the engine while the shaft is rotating.

Application / fitment

Confirmed front-crankshaft applications include selected Buick vehicles equipped with the 350 CID / 5.7 L V8, including:

• 1968–1969 Buick GS 350
• 1968–1980 Buick LeSabre
• 1968–1976 Buick Skylark
• 1968–1969 Buick Special
• 1968–1972 Buick Sportwagon
• 1973–1977 Buick Century
• 1973–1975 Buick Apollo, 1973–1977 Regal and 1977–1978 Riviera with the corresponding engine
• selected late-1960s and early-1970s Jeep J-Series and Wagoneer applications using the Buick 350 engine

Fitment condition: 710173 is a multi-purpose seal number and may be cataloged for other mechanical positions. For an engine application, confirm the front-crankshaft position, the 50 × 70.2 × 10 mm nominal dimensions and compatibility with the timing cover and harmonic-balancer hub.

Installation note: inspect the harmonic-balancer hub sealing surface. A wear groove requires a repair sleeve or component replacement. Lubricate the sealing lip with engine oil and press the seal in squarely with the working lip facing the inside of the engine.

Technical information

• manufacturer: National
• part number: 710173
• type: front crankshaft seal
• design type: 40
• series: 710100
• elastomer material: polyacrylate
• lip helix direction: clockwise spiral
• shaft diameter: 1.969 in / nominal 50.00 mm
• housing bore: 2.756 in / 70.00 mm
• seal outside diameter: 2.764 in / 70.20 mm
• body width: 0.394 in / 10.00 mm
• overall width with side lip: 0.630 in / 16.00 mm
• sale unit: 1 seal