Motive Gear 12BC342 Ring and Pinion Gear Set GM 8.875" 12-Bolt 3.42 Ratio

The Motive Gear 12BC342 is a 3.42 ratio ring and pinion gear set designed for GM Truck 12-Bolt 8.875" rear differentials from 1963-1987. Manufactured with 8620 steel for durability, it features 12-bolt compatibility, making it an ideal replacement or upgrade for GM truck applications.

Key Specifications:

• Gear ratio: 3.42:1 with ring gear diameter of 8.875 inches
• 30-spline pinion with 41 ring gear teeth and 12 pinion gear teeth
• Pinion shaft diameter: 1.438 inches
• Fits 2.76 to 3.42 carriers with 8620 steel construction
• Standard ring gear rotation

Motive Gear is a leading manufacturer of performance drivetrain products, offering a wider range of ring and pinion gearsets than any other aftermarket manufacturer. Their ring and pinions are forged out of 8620 steel, making them quality quiet gears perfect for any vehicle from street use to offroad. All Motive Gear products undergo rigid quality control tests to ensure proper fit, performance, and longevity.

Important Notes:

• The GM 8.875" 12-Bolt Truck differential has carrier breaks at 2.73/2.76-3.42/3.73, meaning if changing from 3.42 gears to 4.56 ratio, you will need a thick gear or new carrier.
• Professional installation recommended with proper setup and break-in procedures
• Installation kit with bearings, seals, and shims sold separately