Overview
The ZF 0501.325.807 PROTECTION CAP is a critical sealing component engineered for heavy-duty construction machinery transmissions. This OEM genuine part fits precisely over exposed ports or sensor cavities within the transmission housing, preventing debris ingress and fluid contamination. The SKU 0501.325.807 is commonly installed on the upper valve body or clutch housing assembly, where it shields internal hydraulic passages from dirt and moisture during operation or maintenance. As a factory-spec component, it ensures a tight, vibration-resistant seal that maintains system pressure integrity.
Symptoms of Failure
- Hydraulic fluid seepage around the cap edge – A worn or cracked 0501.325.807 cap allows oil to weep past the seal, often visible as a thin film on the transmission housing. This is a common long-tail search query for “ZF transmission oil leak at cap.”
- Contaminated transmission fluid – When the protection cap fails, dirt and water enter the system, leading to sludge buildup and accelerated wear. Operators may notice “transmission fluid turning dark quickly” or “debris in oil filter.”
- Erratic gear engagement or slipping – Loss of seal integrity can cause pressure drops in the valve body, resulting in “ZF transmission slipping under load” or “delayed shifting in construction equipment.”
- Visible cap deformation or brittleness – Heat cycles and UV exposure cause the cap to harden or crack, leading to “broken transmission cap replacement needed.”
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0501.325.807 |
| Material | Nitrile rubber (NBR) with steel insert |
| Outer Diameter | 32 mm |
| Inner Diameter | 18 mm |
| Height | 12 mm |
| Weight | 8 g |
| OEM Reference | ZF 0501.325.807 |
| Operating Temperature | -40°C to +120°C |
Compatibility
This protection cap is designed for ZF WG series transmissions commonly used in construction machinery, including models WG180, WG200, and WG210. It also fits select ZF 4WG-200 and 6WG-200 variants. The cap mounts directly onto the transmission housing or valve cover, often adjacent to the 4699101086 HOUSING and the 4699301223 HOUSING. During installation, ensure the 0636302022 SCREW PLUG and 0501319149 SCREW PLUG are torqued to spec to avoid cross-threading.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699101086 | HOUSING | Main transmission housing casting |
| 4699301223 | HOUSING | Clutch housing assembly |
| 0636302022 | SCREW PLUG | Seals oil passages |
| 0501319149 | SCREW PLUG | Drain or fill port plug |
| 0634801038 | SEALING RING | Provides leak-proof seal under plugs |
| 0730365801 | TYPE PLATE | Identification plate for transmission model |
| 0501323165 | SHAFT SEAL | Prevents oil leakage at rotating shafts |
| 4699301222 | COVER | Protects internal components from debris |
| 0634303996 | O-RING | Static seal for housing joints |
| 0630513060 | SNAP RING | Retains bearings and shafts in position |
