Speedo Gear Driven 34 Tooth GM Auto Trans

The TCI Speedo Gear Driven 34 Tooth GM Auto Trans is a replacement speedometer drive gear engineered for General Motors automatic transmissions. This plastic-bodied driven gear features a 34-tooth configuration and is manufactured to original equipment specifications, ensuring accurate speedometer calibration in vehicles equipped with GM 200C, 375B, TH425, 475, or 700R4 transmissions.

The 34-tooth design is critical to speedometer accuracy—the driven gear meshes with the transmission's drive gear to translate driveshaft rotation into speedometer needle movement. TCI's engineering ensures proper tooth profile and diameter tolerances that maintain the correct gear ratio necessary for precise speed readouts. The green plastic construction is durable and compatible with the original mounting interface on these transmission cases. This component is essential for vehicles experiencing speedometer malfunction due to worn or broken drive gears.

Speedometer gear replacement is a common maintenance task for classic car builders, restoration shops, and transmission rebuilders working with these legacy GM transmission platforms. The 34-tooth configuration is standard for specific vehicle/transmission combinations, making verification of your exact application essential before purchase. Improper tooth count results in inaccurate speed readings—either reading high or low depending on the mismatch.

This is a direct replacement part for anyone servicing or rebuilding TH700R4, TH475, TH425, 375B, or 200C transmissions. TCI specializes in transmission components and rebuild supplies, and this gear meets OEM dimensional requirements for proper fit and function.