Overview
The ZF 4660.306.043 PISTON is a critical hydraulic actuation component engineered for the WG 92 and WG 98 series transmissions. This OEM genuine part functions as the primary force-transfer element within the clutch or brake piston assembly, converting hydraulic pressure into precise mechanical movement for gear engagement. The SKU 4660.306.043 sits directly inside the TRANSMISSION HOUSING, where it seals against the HOUSING II to ensure reliable shift performance under heavy-duty industrial loads.
Symptoms of Failure
- Erratic gear engagement or delayed shifting: When the 4660.306.043 piston wears, hydraulic pressure bleeds past the seals, causing sluggish or incomplete clutch pack application.
- Internal transmission oil leaks: A cracked or scored piston surface allows ATF to bypass, often visible as wetness around the bell housing or cooler lines.
- Loss of torque under load: Worn piston travel reduces clamping force on clutch discs, leading to power loss during acceleration or uphill operation.
- Abnormal metallic debris in oil pan: Piston edge wear generates fine aluminum or steel particles that contaminate the hydraulic circuit.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 4660.306.043 |
| Material | High-strength aluminum alloy with anodized surface |
| Outer Diameter | ~120 mm (estimated) |
| Inner Diameter | ~85 mm (estimated) |
| Height | ~35 mm (estimated) |
| Weight | 0.45 kg (estimated) |
| OEM Reference | ZF 4660.306.043 |
| Seal Compatibility | Requires O-RING (0634100317) and O-RING (0634306311) |
Compatibility
This piston is designed for ZF WG series powershift transmissions, specifically the WG 92 and WG 98 models. It is also compatible with WG180, WG200, and WG210 variants that share the same hydraulic piston bore dimensions. The part interfaces directly with the CYLINDRICAL PIN for alignment and the TYPE PLATE for identification. Always verify your transmission serial number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4660101017 | TRANSMISSION HOUSING | Main structural casing for gear and piston assembly |
| 4660301054 | HOUSING II | Secondary housing supporting piston bore |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for piston positioning |
| 0769123894 | TYPE PLATE | Identification tag for transmission model |
| 0750100022 | SCREW PLUG | Seals hydraulic test ports |
| 4660221029 | SUCTION TUBE | Oil pickup from pan to pump |
| 0634100317 | O-RING | Static seal for piston outer diameter |
| 0636103273 | CAP SCREW | Fastener for housing retention |
| 0634306311 | O-RING | Dynamic seal for piston inner bore |
| 4660321029 | FIXING PLATE | Locks piston retaining ring |
