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National 253747 Automatic Transmission Oil Pump Seal - Front
| Brand | National 253747 |
|---|---|
| Position | Front |
| Housing Bore (Inch) | 0.875 |
| Housing Bore (MM) | 22.230 |
| Inside Diameter | 0.625 |
| Inside Diameter | 15.880 |
| Material | Nitrile |
| Outside Diameter | 0.880 |
| Outside Diameter | 22.350 |
| Outside Diameter (Inch) | 0.880 |
| Outside Diameter (mm) | 22.350 |
| Part Description | Oil Seal |
| Sealing Material | Nitrile |
| Series | 250000 |
| Shaft (Inch) | 0.625 |
| Shaft (MM) | 15.880 |
| Thickness | 0.125 |
| Thickness | 3.180 |
| Type | 25 |
| Unit of Dimension | Inch |
| Width (Inch) | 0.125 |
| Width (mm) | 3.180 |
| Fits | Chevrolet, Oldsmobile, and Pontiac · 18 vehicles |
Nitrile seal. Provides dependable sealing performance in transmission applications.
Oil seal. Helps keep transmission fluid contained where it belongs.
National heritage. Backed by more than 75 years of sealing expertise.
Cross-references AMS Automotive 6120, National 253747 and 0704-6183 for the same application. See all 3.
Automatic Transmission Oil Pump Seal for Front Applications
The National 253747 automatic transmission oil pump seal is built for front-position applications that require a precise sealing fit. It uses nitrile sealing material and measures 0.625 in. inside diameter, 0.880 in. outside diameter, and 0.125 in. thickness for a compact OE-style seal profile.
Fits 1982-1984 Chevrolet Cavalier, front; Fits 1982-1984 Chevrolet Celebrity, front; Fits 1982-1984 Oldsmobile Cutlass Ciera, front; Fits 1983-1984 Oldsmobile Firenza, front; Fits 1982-1984 Pontiac 6000, front; Fits 1982-1984 Pontiac J2000/J2000 Sunbird, front; Fits 1984 Pontiac Fiero, front.
Key Features
- National 253747 automatic transmission oil pump seal
- Nitrile sealing material for transmission sealing applications
- 0.625 in. shaft diameter and 0.875 in. housing bore specification
- 0.880 in. outside diameter and 0.125 in. width for front-position fitment
- Series 250000, Type 25 oil seal design
- Cross-references AMS Automotive 6120 and 0704-6183 for the same application
Detailed Description
National 253747 is an automatic transmission oil pump seal designed around the listed shaft, housing bore, and dimensional requirements. The nitrile construction supports sealing performance in transmission environments where accurate sizing matters, and the part description identifies it as an oil seal in National’s 250000 series. This part number is a direct match for front applications on vehicles such as the Chevrolet Cavalier, Chevrolet Celebrity, Oldsmobile Cutlass Ciera, Pontiac 6000, Pontiac J2000/J2000 Sunbird, Oldsmobile Firenza, and Pontiac Fiero within the listed model years. If you are replacing a leaking front transmission pump seal, National 253747 provides the specified dimensions and material profile for the application.
What It Helps Address
- Transmission fluid leakage at the front oil pump seal area
- Seal wear from age, heat, and fluid exposure
- Incorrect seal sizing during transmission service
- Loss of sealing integrity around the pump shaft
- Front transmission seepage on listed Chevrolet, Oldsmobile, and Pontiac applications
Installation Notes and Tips
Verify shaft diameter, housing bore, outside diameter, and width before installation. Clean the sealing surface and inspect the pump bore for wear, scoring, or debris that could affect sealing. Use the exact front-position application listed for your vehicle, and confirm the transmission service procedure for the specific model year before assembly.
Quality Assurance
National has supplied sealing solutions for more than 75 years and continues to develop sealing components for modern vehicle service needs. Part number 253747 is built to the stated dimensional and material specifications for the listed applications.
| Year | Make | Model | Transmission | Position | Notes |
|---|---|---|---|---|---|
| 1984 | Chevrolet | Cavalier | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1984 | Chevrolet | Celebrity | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1984 | Oldsmobile | Cutlass Ciera | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1984 | Oldsmobile | Firenza | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1984 | Pontiac | 6000 | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1984 | Pontiac | Fiero | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1984 | Pontiac | J2000 Sunbird | Automatic | Front | 1st Design; with 0.88 (in) O.D.; with 0.125 (in) Width |
| 1983 | Chevrolet | Cavalier | Automatic | Front | — |
| 1983 | Chevrolet | Celebrity | Automatic | Front | — |
| 1983 | Oldsmobile | Cutlass Ciera | Automatic | Front | — |
| 1983 | Oldsmobile | Firenza | Automatic | Front | — |
| 1983 | Pontiac | 6000 | Automatic | Front | — |
| 1983 | Pontiac | J2000 | Automatic | Front | — |
| 1982 | Chevrolet | Cavalier | Automatic | Front | — |
| 1982 | Chevrolet | Celebrity | Automatic | Front | — |
| 1982 | Oldsmobile | Cutlass Ciera | Automatic | Front | — |
| 1982 | Pontiac | 6000 | Automatic | Front | — |
| 1982 | Pontiac | J2000 | Automatic | Front | — |
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