ZF 4474.393.030 PINION | OEM Genuine Part

Overview

The ZF 4474.393.030 Pinion is a critical input shaft component engineered for heavy-duty construction machinery transmissions. This OEM genuine part transfers rotational force from the torque converter to the planetary gear sets, initiating the first stage of gear reduction. The SKU 4474.393.030 identifies a precision-ground helical pinion designed to mesh with the main drive gear cluster, ensuring smooth power delivery under extreme load conditions. Manufactured from case-hardened alloy steel, this pinion maintains tight tolerances to minimize backlash and vibration in ZF drivetrains. Its location within the transmission housing makes it essential for both forward and reverse gear engagement in wheel loaders, graders, and dump trucks.

Symptoms of Failure

When the ZF 4474.393.030 pinion wears, operators often notice distinct performance degradation. The following failure indicators are common:

• Whining or grinding noise during acceleration – A high-pitched metallic sound from the transmission bell housing indicates tooth surface pitting or chipping on the pinion gear.
• Intermittent gear slippage under load – Worn pinion teeth fail to maintain positive engagement, causing the transmission to momentarily lose torque when climbing grades or moving heavy material.
• Metal particles in transmission fluid – Flakes or silver debris on the magnetic drain plug signal advanced spalling of the pinion’s hardened surface layer.
• Hard shifting or delayed engagement – Increased friction from a damaged pinion creates resistance in the shift sequence, particularly when moving from neutral to first gear.

Technical Specifications

Compatibility

This pinion is designed for ZF’s modular transmission families used in construction machinery. Based on its spline dimensions and tooth geometry, the 4474.393.030 fits the following models:

• ZF WG180 – 6-speed powershift transmission (common in compact wheel loaders)
• ZF WG200 – 4-speed heavy-duty transmission (used in graders and backhoe loaders)
• ZF WG210 – 6-speed transmission with integrated torque converter (found in telescopic handlers)
• ZF Ergopower 3 – Automated manual transmission for medium-duty construction vehicles

Always verify the transmission serial number before installation. This pinion is not compatible with ZF AS Tronic or Ecolite series units.