Overview
The ZF 5841.302.058 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 shift gears within the transmission valve body. Positioned within the piston housing assembly, the 5841.302.058 piston ensures precise oil flow control and consistent clamping force during gear changes. As a direct OEM replacement, this piston restores factory-spec shift timing and prevents internal pressure loss that can degrade transmission performance over time.
Symptoms of Failure
- Delayed or harsh gear engagement – When the 5841.302.058 piston wears, hydraulic pressure drops, causing noticeable hesitation or jarring shifts between forward and reverse gears.
- Internal transmission oil leaks – A cracked or scored piston seal allows ATF to bypass the piston, leading to low fluid levels and visible drips near the transmission pan or bell housing.
- Slipping in higher gears – Worn piston surfaces fail to maintain clutch pack pressure, resulting in RPM flare without corresponding acceleration, especially under load.
- Erratic shift patterns – Inconsistent piston travel causes the transmission to hunt between gears or skip shifts entirely, often accompanied by warning lights on the dashboard.
Technical Specifications
| Specification | Value |
|---|---|
| OEM Part Number | 5841.302.058 |
| Material | Hardened alloy steel with PTFE seal coating |
| Outer Diameter | 58.4 mm |
| Inner Diameter | 32.0 mm |
| Height | 28.5 mm |
| Weight | 0.34 kg (0.75 lbs) |
| Surface Finish | Ground and polished to 0.4 µm Ra |
| Operating Pressure | 12–18 bar (174–261 psi) |
Compatibility
This piston is specifically designed for ZF WG-series powershift transmissions. Verified compatibility includes the WG100, WG130, and WG131 models. It may also be suitable for select WG180 and WG200 variants with matching piston bore dimensions. Always cross-reference your transmission serial number with the 5841.302.058 part number to confirm fitment. For differential-related repairs in these transmissions, consider the 5838109010: DIFFERENTIAL and the 2093209023: DIFFERENTIAL for complete driveline restoration.
During piston replacement, inspect the 0750117075: TAPER ROLLER BEARING for wear, as bearing play can accelerate piston seal degradation. The 5838300626: DIFFERENTIAL HOUSING should also be checked for cracks or distortion when servicing the piston assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 5838109010 | DIFFERENTIAL | Distributes torque between drive wheels |
| 0750117075 | TAPER ROLLER BEARING | Supports rotating shafts with axial/radial loads |
| 2093209023 | DIFFERENTIAL | Secondary differential for multi-axle drives |
| 5838300626 | DIFFERENTIAL HOUSING | Encloses differential gear set |
| 0631329088 | SPRING PIN | Secures piston and linkage assemblies |
| 5838300811 | THRUST WASHER | Reduces axial friction between rotating parts |
| 5838300721 | AXLE BEVEL GEAR | Transfers power at 90-degree angles |
| 5838300633 | AXLE | Transmits rotational force to wheel hubs |
| 5838300753 | THRUST WASHER | Controls end-play in planetary gear sets |
| 5838300818 | THRUST WASHER | High-load washer for differential carrier |
