Automatic Transmission Ring Gear Details

ATP Parts ZA-504 is an automatic transmission ring gear built to match original fit and function. It uses 188 teeth and a 12-pitch flywheel pattern, making it a direct replacement for worn or broken starter engagement teeth.

• 188-tooth ring gear for starter engagement.
• 12-pitch flywheel specification.
• 14.728-inch inside diameter and 16.102-inch outside diameter.
• 0.375-inch thickness with no chamfer.
• Fits Ford truck applications from the late 1960s through the mid-1970s.

Fitment and Application

Fits 1968-1976 Ford F-100, N/A. Fits 1975-1976 Ford F-150, N/A. Fits 1968-1976 Ford F-250, N/A. Fits 1968-1976 Ford F-350, N/A. Fits 1964-1966 Ford F-350, N/A. This part cross-references Pioneer Automotive Industries (e.g., FRG-188T) for the same application.

Use ATP Parts ZA-504 when the original ring gear teeth are worn, chipped, or broken from repeated starter engagement. The Ford F-100, Ford F-250, and Ford F-350 applications listed here rely on the ring gear to transfer starter motor engagement to the engine for cranking.

What It Helps Solve

• Starter engagement problems caused by damaged ring gear teeth.
• Cranking issues related to worn tooth profiles.
• Noise from the starter slipping or missing the gear teeth.
• Replacement needs after ring gear inspection confirms tooth wear or breakage.

Installation Notes and Tips

Confirm tooth count, pitch, and diameters before installation. Match the ring gear to the flywheel specification and inspect the starter drive for wear at the same time. Proper alignment is important for reliable starter engagement.

Quality Assurance

ATP Parts designs this ring gear to fit and function like the original component for durability and long service life.