ATP Parts Z-258 Automatic Transmission Flexplate

ATP Parts Z-258 Flexplate Overview

ATP Parts Z-258 is an automatic transmission flexplate built for vehicles that rely on a 142-tooth ring gear and a 11.938-inch outside diameter. It connects the engine to the torque converter and starter system, making accurate fitment critical for smooth operation in Buick, Chevrolet, Oldsmobile, and Pontiac applications.

When a flexplate cracks or shears, it cannot be repaired and must be replaced. This ATP Parts flexplate uses high-quality steel and the correct bolt-hole spacing and ring gear tooth pattern to match the original part.

Key Features

• Automatic transmission flexplate for engine-to-transmission connection
• 142 teeth for starter engagement
• 11.938-inch outside diameter
• 8.5 mm mounting hole diameter
• 12-pitch flywheel specification
• High-quality steel construction for durability
• OE-style bolt spacing and ring gear tooth layout
• ATP Parts Part Number: Z-258

Detailed Product Description

ATP Parts Z-258 is engineered for automatic transmission vehicles that require a 142-tooth flexplate with the listed diameter and mounting dimensions. It is used in a wide range of fitments including 2000-2003 Chevrolet Impala, 1998-2003 Pontiac Grand Prix, 1995-2003 Buick Century, and other GM passenger cars and minivans listed below. The part number Z-258 is also cross-referenced to Pioneer Automotive Industries FRA-426 for the same application.

Because flexplates are exposed to repeated expansion and contraction during engine operation, fatigue can lead to cracks, broken teeth, or shearing around the mounting area. Replacing a damaged flexplate with the correct specification helps restore starter engagement and torque converter connection.

What This Flexplate Helps Fix

• Cracked or fractured flexplate material
• Starter engagement problems caused by damaged ring gear teeth
• Noise from a flexplate that has begun to fail
• Torque converter connection issues from worn mounting points
• Damage related to a sheared or distorted flexplate

Fitment Notes

• Fits 2002-2005 Buick Rendezvous, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1995-2003 Buick Century, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 2000-2003 Chevrolet Impala, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1999-2003 Chevrolet Malibu, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2003 Chevrolet Monte Carlo, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 2002-2003 Oldsmobile Alero, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2003 Oldsmobile Silhouette, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 2001-2003 Pontiac Aztek, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2003 Pontiac Grand Am, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2003 Pontiac Grand Prix, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1999-2003 Pontiac Montana, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2002 Chevrolet Cavalier, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2001 Chevrolet Lumina, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1993 Chevrolet Lumina, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998-2001 Pontiac Sunfire, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1999-2000 Oldsmobile Alero, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1998-1999 Oldsmobile Cutlass, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1996-1999 Pontiac Trans Sport, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1998 Buick Skylark, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1995 Buick Skylark, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1997-1998 Chevrolet Malibu, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1998 Oldsmobile Achieva, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1996-1997 Buick Skylark, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1994 Buick Skylark, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1996-1997 Chevrolet Cavalier, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1993-1994 Chevrolet Cavalier, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1993-1997 Chevrolet Lumina, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1995-1997 Chevrolet Monte Carlo, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1994-1997 Oldsmobile Achieva, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1997 Oldsmobile Cutlass, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1994-1997 Oldsmobile Cutlass Supreme, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1996-1997 Oldsmobile Silhouette, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1994-1997 Pontiac Grand Am, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1993-1997 Pontiac Grand Prix, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1996-1997 Pontiac Sunfire, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1995-1996 Buick Regal, N/A; Teeth: 142; Outer Diameter: 11.87"
• Fits 1993-1996 Chevrolet Corsica, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1993-1996 Chevrolet Lumina APV, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1994-1996 Oldsmobile Cutlass Ciera, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1993-1994 Buick Century, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight
• Fits 1994 Buick Regal, N/A; Teeth: 142; Outer Diameter: 11.87"; w/o Weight

Installation Notes

Verify tooth count, outside diameter, and mounting-hole spacing before installation. Confirm whether your application requires the weighted or non-weighted version, since some listed vehicles specify w/o Weight. Inspect the starter ring gear, torque converter mounting points, and crankshaft flange for wear or damage before assembly.

For best results, match the flexplate to the exact vehicle configuration listed in the fitment data for your Buick, Chevrolet, Oldsmobile, or Pontiac application. The part number Z-258 should be checked against the original flexplate dimensions before installation.

Quality Assurance

ATP Parts builds this flexplate from high-quality steel with OE-style dimensions to support proper fit and long service life. The design follows the original bolt-hole spacing and ring gear tooth pattern for the listed applications, helping maintain correct starter engagement and torque converter alignment.