ATP Parts KO-1 Automatic Transmission Oil Pump Seal - Front or Outer

ATP KO-1 Automatic Transmission Oil Pump Seal

ATP Parts KO-1 is an exact-fit automatic transmission oil pump seal for a wide range of Ford, Lincoln, and Mercury applications. It is built for direct replacement use where the transmission pump seal must maintain fluid control and proper sealing at the pump interface.

• Exact-fit replacement seal for automatic transmission oil pump service
• Inner diameter: 2.1875 inches
• Fits N/A, outer, and front positions as listed by application
• Designed for Ford F-150, Ford Bronco, Mustang, Thunderbird, and related vehicles
• ATP transmission seal and gasket replacement part, part number KO-1

Application Coverage

Compatible with a broad range of classic and late-model Ford, Lincoln, and Mercury vehicles, including Ford F-150, Ford Bronco, Mustang, Thunderbird, E-Series vans, F-Series trucks, and select Lincoln Town Car and Mercury Grand Marquis applications. Fits 1964-1996 Ford, Lincoln, and Mercury models listed in the fitment data, with position-specific coverage such as front, outer, and N/A configurations.

ATP KO-1 is an OE-style sealing component for automatic transmission pump service. The seal helps maintain the hydraulic seal at the oil pump area, which is critical for stable transmission operation and fluid retention. If you are replacing a worn pump seal during transmission repair, rebuild, or service work, KO-1 provides the specified inner diameter and application match for the listed vehicles.

Common Problems This Seal Addresses

• Transmission fluid leakage at the oil pump seal area
• Loss of hydraulic sealing during transmission service
• Seal wear found during rebuild or overhaul work
• Poor sealing after pump removal and reinstallation
• Fitment issues when replacing an incorrect or mismatched seal

Installation Notes and Tips

Verify the transmission application, position, and inner diameter before installation. Clean the pump bore and sealing surfaces thoroughly, and inspect the pump and related components for wear or damage before fitting the new seal. Because fitment varies by year, make, model, and position, confirm the vehicle listing for your specific Ford, Lincoln, or Mercury application before assembly.

Quality Assurance

ATP Parts describes its transmission seals and gaskets as exact-fit replacement parts. KO-1 is produced as a direct replacement sealing component for the listed applications, with fitment coverage documented for Ford F-150, Mustang, Bronco, Thunderbird, and related vehicles.