Overview
The ZF 4657.330.019 DIAPHRAGM is a critical pneumatic actuation component engineered for the WG190, WG210, and WG230 series transmissions. This OEM genuine part functions as a flexible sealing membrane within the clutch or shift actuator assembly, converting air pressure into precise mechanical movement to engage and disengage gears. The SKU 4657.330.019 is manufactured to exacting ZF tolerances, ensuring reliable modulation of hydraulic or pneumatic circuits. This diaphragm sits directly within the actuator housing, working in concert with the 4657101031: TRANSMISSION HOUSING to maintain system pressure integrity.
Symptoms of Failure
- Erratic gear engagement or delayed shifting — A worn diaphragm cannot maintain consistent pressure, causing hesitation when the transmission attempts to shift under load.
- External oil or air leaks near the actuator housing — Cracks or perforations in the rubber membrane allow pressurized fluid or air to escape, often visible as wet spots around the 4657201027: HOUS.FRONT SECT.
- Intermittent gear slipping during acceleration — Loss of diaphragm elasticity reduces clamping force, leading to momentary loss of torque transfer.
- Increased transmission noise or harsh engagement — A stiff or torn diaphragm fails to dampen actuator movement, transmitting vibration directly into the 4657201020: HOUSING REAR PART.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 4657.330.019 |
| Material | Nitrile rubber (NBR) with fabric reinforcement |
| Outer Diameter | 180 mm (estimated) |
| Thickness | 4.5 mm (estimated) |
| Operating Pressure Range | 6–12 bar |
| Temperature Range | -40°C to +120°C |
| Weight | 0.15 kg (estimated) |
| OEM Reference | ZF 4657.330.019 |
Compatibility
This diaphragm is specifically designed for ZF WG-series powershift transmissions. It is a direct replacement for the following models: WG180, WG190, WG200, WG210, WG230. The part interfaces directly with the actuator bore and is secured by a 0631306792: CYLINDRICAL PIN that aligns the diaphragm with the shift fork mechanism. Always verify your transmission serial number against the WG series prefix before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101031 | TRANSMISSION HOUSING | Main structural casing enclosing gear sets and shafts |
| 4657201027 | HOUS.FRONT SECT | Forward section of the transmission housing, supports input shaft |
| 4657201020 | HOUSING REAR PART | Rear housing section, contains output bearing and PTO interface |
| 0631306792 | CYLINDRICAL PIN | Locating pin for actuator and diaphragm alignment |
| 0636100801 | CAP SCREW | Fastener for securing housing sections |
| 4656301148 | FIXING PLATE | Retains diaphragm and actuator components |
| 4657301032 | SCREEN SHEET | Fine mesh filter for hydraulic fluid return line |
| 4657301033 | SCREEN SHEET | Coarse mesh filter for suction side of pump |
| 0636100803 | CAP SCREW | High-tensile bolt for actuator cover |
| 4681301040 | OIL FEED.HOUSG. | Distributes pressurized oil to clutch packs |
Frequently Asked Questions
Q: How do I know if my ZF WG190 needs a new diaphragm?
A: If you notice slow or incomplete gear engagement, especially in cold weather, or see oil weeping from the actuator vent, the diaphragm is likely compromised. A pressure test of the actuator circuit will confirm leakage across the 4657.330.019 seal.
Q: Can I install this diaphragm without removing the transmission?
A: Yes, in most WG210 and WG230 installations, the diaphragm is accessible by removing the actuator cover and the 4656301148: FIXING PLATE. However, on WG180 models, partial removal of the 4657201027: HOUS.FRONT SECT may be required for clearance.
Q: Is the 4657.330.019 compatible with aftermarket actuator kits?
A: This OEM genuine part is dimensionally identical to the original ZF production diaphragm. It will fit any WG-series actuator that uses the standard 180 mm bolt pattern, but we recommend replacing the 0631306792: CYLINDRICAL PIN simultaneously to ensure proper centering.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
Request a Quote →
