ZF 1203.308.078 SPEEDOMETER PINION for WG200 | OEM Genuine Part

Overview

The ZF 1203.308.078 SPEEDOMETER PINION is a critical component within the WG200 series transmission, responsible for accurately transmitting rotational speed data from the output shaft to the vehicle’s speedometer or electronic control unit (ECU). This genuine OEM part, identified by SKU 1203.308.078, sits directly in the transmission housing, engaging with the output gear to generate precise pulse signals. Without a properly functioning pinion, speed readings become erratic or fail entirely, compromising vehicle diagnostics and driveline performance. As a factory-spec replacement, this pinion ensures seamless integration with your ZF transmission system.

Symptoms of Failure

When the ZF 1203.308.078 SPEEDOMETER PINION begins to wear, operators may notice these specific failure indicators:

• Erratic speedometer needle fluctuations – The needle jumps or drops unexpectedly, especially during steady cruising, indicating gear tooth wear or internal damage.
• Complete loss of speed signal – The speedometer reads zero while the vehicle is moving, often accompanied by a check engine light or transmission warning code.
• Oil seepage around the pinion housing – Worn seals or a cracked pinion body allow transmission fluid to escape, leading to low fluid levels and potential gear slipping.
• Incorrect odometer mileage accumulation – The odometer fails to record distance accurately, causing compliance issues for fleet operators.

Technical Specifications

Compatibility

This ZF 1203.308.078 SPEEDOMETER PINION is engineered primarily for the WG200 series transmissions, including models such as the WG180, WG200, and WG210. It is also compatible with certain variants of the ZF Ecomat and Ecolife series that share the same output shaft interface. Always verify your transmission model and housing configuration before installation to ensure a precise fit.

Installation Notes

When replacing this pinion, it is recommended to inspect and replace associated mounting hardware. The 4460165051 CONSOLE and 4460368311 CONSOLE provide the structural support for the pinion assembly. Secure the unit using a 0636011429 HEXAGON SCREW and a 0730100365 WASHER to prevent loosening from vibration. Proper torque application ensures a leak-free seal and accurate signal transmission.

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