ZF 5840.303.171 PISTON for WG100/WG130/WG131 | OEM Genuine Part

Overview

The ZF 5840.303.171 PISTON is a critical hydraulic actuation component engineered for the WG100, WG130, and WG131 transmission series. This OEM genuine part converts hydraulic pressure into mechanical force to engage clutch packs and modulate gear shifts within the planetary gearset. As a precision-machined component, the SKU 5840.303.171 sits within the piston housing assembly, directly interfacing with the clutch drum to ensure smooth power transfer. When paired with a properly functioning 5838109007: DIFFERENTIAL, this piston maintains consistent oil flow and shift timing across all operating ranges.

Symptoms of Failure

• Delayed or harsh shifting: A worn 5840.303.171 piston often causes hesitation between gears or abrupt engagement, particularly during upshifts from 2nd to 3rd gear.
• Internal transmission oil leaks: Cracks or seal degradation on the piston surface allow pressurized ATF to bypass, leading to low line pressure and visible drips from the bell housing area.
• Slipping in forward gears: Insufficient clamping force from a failing piston results in clutch pack slippage under load, especially noticeable when climbing grades or towing.
• Erratic shift patterns: The transmission may hunt for gears or fail to hold a selected gear due to inconsistent hydraulic pressure from a compromised piston.

Technical Specifications

Compatibility

This piston is specifically engineered for ZF WG-series powershift transmissions used in off-highway and industrial equipment. Primary compatibility includes the WG100, WG130, and WG131 models. It also fits select variants of the WG180 and WG200 series when used in conjunction with the correct 0750117075: TAPER ROLLER BEARING and 2095209019: DIFFERENTIAL assemblies. Always verify your transmission serial number before installation. The 0631329086: SPRING PIN is also required to secure the piston retainer during reassembly.

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