ATP Parts ZA-509 Clutch Flywheel Ring Gear

ATP ZA-509 Clutch Flywheel Ring Gear

ATP Parts ZA-509 is a clutch flywheel ring gear built for Jeep applications that rely on a 164-tooth starter engagement pattern. It is made to match the original part’s fit and function, helping restore reliable cranking when worn or broken ring gear teeth are the cause.

With a 13.83-inch outside diameter, 12.82-inch inside diameter, and 0.42-inch thickness, this ring gear is specified for direct replacement use in select Jeep Cherokee, Wrangler, Grand Cherokee, Comanche, Wagoneer, J10, J20, CJ5, CJ7, and Scrambler applications. The ATP ZA-509 is a practical choice when the starter no longer engages cleanly with the flywheel ring gear.

Key Features

• Part number: ZA-509
• Clutch flywheel ring gear for transmission and flywheel service
• 164 teeth for starter motor engagement
• Outside diameter: 13.83 inches
• Inside diameter: 12.82 inches
• Thickness: 0.42 inches
• Pitch flywheels: 12/14
• Ring gear chamfer: none
• Built to match original fit and function for Jeep flywheel applications

Detailed Description

The ring gear is the toothed component that the starter motor engages to crank the engine. When those teeth become worn, chipped, or broken, starting problems can follow. ATP Parts ZA-509 is engineered as an OE-style replacement ring gear for Jeep models that use a 164-tooth setup, including Jeep Cherokee, Jeep Wrangler, and Jeep Grand Cherokee applications listed below. This part number, ZA-509, is also referenced in the aftermarket under several cross-reference numbers for the same application. This part cross-references AMS Automotive 4411 and Pioneer Automotive Industries FRG-164A for the same application.

Vehicle Fitment

• Fits 1987-1998 Jeep Cherokee, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1974-1983 Jeep Cherokee, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1997-1998 Jeep Wrangler, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1987-1995 Jeep Wrangler, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1993-1994 Jeep Grand Cherokee, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1987-1992 Jeep Comanche, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1987-1990 Jeep Wagoneer, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1972-1983 Jeep Wagoneer, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1974-1987 Jeep J10, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1976-1986 Jeep CJ7, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1981-1985 Jeep Scrambler, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1972-1983 Jeep CJ5, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"
• Fits 1974-1983 Jeep J20, N/A. Notes: Teeth: 164, Outer Diameter: 13.83"

Common Problems This Part Can Address

• Starter motor grinding during engine cranking
• Engine no-start caused by damaged ring gear teeth
• Intermittent starter engagement on Jeep Cherokee, Wrangler, or Grand Cherokee applications
• Visible wear, cracking, or broken teeth on the flywheel ring gear
• Repeated starter slip or incomplete engagement with the flywheel

Installation Notes and Tips

Confirm tooth count, outside diameter, inside diameter, and flywheel pitch before installation. Because this is a flywheel ring gear service part, proper alignment and secure seating on the flywheel are important for starter engagement. Verify the existing flywheel condition and inspect the starter drive before reassembly so the new ring gear is not installed over a related starting-system fault.

Quality Assurance

ATP Parts designs this ring gear to fit and function like the original component, with the goal of restoring dependable starter engagement and long service life in the listed Jeep applications.