Overview
The ZF 0501.217.240 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 valve body assembly. Positioned inside the 4663101001: HOUSING, this piston ensures precise oil flow control and consistent clamping force. The SKU 0501.217.240 is a direct factory replacement, guaranteeing exact sealing geometry and material hardness for long service intervals in heavy-duty industrial drivetrains.
Symptoms of Failure
- Erratic gear engagement or delayed shifting — A worn piston fails to build adequate hydraulic pressure, causing hesitation when shifting between forward and reverse gears.
- Internal transmission oil leaks — Degraded piston seals allow pressurized ATF to bypass, leading to low line pressure and visible drips near the housing mating surface.
- Clutch slippage under load — Insufficient piston stroke reduces clutch pack clamping force, resulting in RPM flare during acceleration or uphill operation.
- Metallic debris in the oil pan — Scored piston surfaces shed aluminum particles into the hydraulic circuit, contaminating the 0631306816: CYLINDRICAL PIN and valve body bores.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (OEM) | 0501.217.240 |
| Material | High-strength aluminum alloy (EN AW-6082) |
| Outer Diameter | 68.5 mm |
| Inner Diameter | 42.0 mm |
| Height | 32.8 mm |
| Weight | 0.185 kg |
| Surface Finish | Hard anodized (40 µm) |
| Seal Grooves | 2 x O-ring (DIN 3771) |
| OEM Reference | ZF 0501.217.240 |
Compatibility
This piston is specifically designed for ZF WG-series powershift transmissions used in construction and agricultural machinery. Verified compatible models include:
- ZF WG100 (4-speed, 100-150 hp)
- ZF WG130 (4-speed, 130-180 hp)
- ZF WG131 (4-speed, 150-200 hp)
It also fits select variants of the WG180 and WG200 when used with the correct 4663301025: COVER and 0636100817: CAP SCREW kit. Always verify the piston bore diameter against your transmission housing before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4663101001 | HOUSING | Encloses piston and valve assembly |
| 4663301025 | COVER | Seals the piston chamber |
| 0631306816 | CYLINDRICAL PIN | Aligns piston guide bore |
| 0636100817 | CAP SCREW | Secures cover to housing |
| 4656301148 | FIXING PLATE | Retains piston spring assembly |
| 0636611009 | STUD | Mounting bolt for valve body |
| 0634303928 | O-RING | Seals piston outer diameter |
| 4475280099 | SCREW PLUG | Closes oil gallery port |
| 0634303266 | O-RING | Seals screw plug |
| 4475280018 | SCREW PLUG | Secondary port plug |
