ATP Parts Z-123 Automatic Transmission Flexplate

Automatic Transmission Flexplate for Pontiac Applications

ATP Parts Z-123 is an automatic transmission flexplate built for Pontiac vehicles that use a 166-tooth ring gear and a 13.938-inch outside diameter. It connects the engine to the torque converter and starter ring gear, making correct fit and tooth count critical for reliable operation.

Use this flexplate when replacing a cracked, sheared, or otherwise damaged unit on select Pontiac Bonneville, Catalina, Firebird, Grand Prix, LeMans, GTO, Tempest, Grand Am, Laurentian, and Parisienne applications. ATP Parts Z-123 is made from high-quality steel with OE-style bolt hole spacing and ring gear teeth.

Key Features

• Automatic transmission flexplate for Pontiac applications
• 166 teeth for starter engagement
• 13.938-inch outside diameter
• 2.75-inch inside diameter
• 11.25-inch mounting hole diameter
• High-quality steel construction
• OE-style bolt hole spacing and ring gear tooth layout
• Pitch flywheels: 12 to 14

Detailed Product Overview

Flexplates are a wear item in automatic transmission systems because they repeatedly expand and contract as engine speed changes. Over time, that stress can lead to cracks or shearing, and a damaged flexplate should be replaced rather than repaired. ATP Parts Z-123 is engineered to match the original part’s critical dimensions, including tooth count, diameter, and mounting pattern, for proper starter engagement and torque converter connection. This part cross-references Pioneer Automotive Industries FRA-103 for the same application.

Fits 1975-1976 Pontiac Bonneville, N/A; Fits 1965-1971 Pontiac Bonneville, N/A; Fits 1965-1976 Pontiac Catalina, N/A; Fits 1969-1976 Pontiac Firebird, N/A; Fits 1975-1976 Pontiac Grand LeMans, N/A; Fits 1965-1976 Pontiac Grand Prix, N/A; Fits 1976 Pontiac Laurentian, N/A; Fits 1968-1976 Pontiac LeMans, N/A; Fits 1976 Pontiac Parisienne, N/A; Fits 1974-1975 Pontiac Grand Am, N/A; Fits 1972-1974 Pontiac Bonneville, N/A; Fits 1972-1974 Pontiac Catalina, N/A; Fits 1967-1974 Pontiac Catalina, N/A; Fits 1971-1974 Pontiac Firebird, N/A; Fits 1967 Pontiac Firebird, N/A; Fits 1967-1974 Pontiac Firebird, N/A; Fits 1974 Pontiac Grand Am, N/A; Fits 1968-1974 Pontiac LeMans, N/A; Fits 1970-1973 Pontiac Grand Prix, N/A; Fits 1966-1973 Pontiac GTO, N/A; Fits 1972-1973 Pontiac LeMans, N/A; Fits 1965-1967 Pontiac LeMans, N/A; Fits 1970-1971 Pontiac Bonneville, N/A; Fits 1970-1971 Pontiac GTO, N/A; Fits 1965 Pontiac GTO, N/A; Fits 1970 Pontiac Tempest, N/A; Fits 1968-1969 Pontiac Tempest, N/A; Fits 1965-1967 Pontiac Tempest, N/A.

Common Problems This Part Addresses

• Cracked flexplate from repeated engine-speed cycling
• Sheared flexplate material around the mounting area
• Starter engagement issues caused by worn or damaged ring gear teeth
• Torque converter connection problems from incorrect bolt spacing
• Noise or drivability concerns related to a failing flexplate

Installation Notes and Tips

Confirm tooth count, outside diameter, and mounting pattern before installation. This flexplate is listed for select Pontiac applications and some fitments note THM400-only or w/o weight requirements, so verify your transmission and engine combination against the vehicle notes before ordering. Inspect the starter, torque converter, and related hardware for wear before installing the replacement flexplate.

Quality Assurance

ATP Parts Z-123 is manufactured from steel with OE-style dimensions to support proper fitment and long-term durability in the listed Pontiac applications. SFI approval is not indicated for this part.