Overview
The ZF 4475.280.085 is a precision-engineered OEM genuine component specifically designed for the WG 100 and WG 110 series transmissions. This part functions as a critical hydraulic control element within the valve body assembly, regulating fluid pressure and flow to ensure smooth gear engagement and consistent clutch application. As an OEM genuine part, the SKU 4475.280.085 guarantees exact fitment and factory-specified tolerances, eliminating the risk of premature wear associated with aftermarket alternatives. This component works in direct conjunction with the 4651101007: TRANSMISSION HOUSING to maintain proper hydraulic circuit integrity.
Symptoms of Failure
- Erratic shift timing and harsh engagement: When the 4475.280.085 wears, internal spool valves may stick, causing delayed or abrupt gear changes that worsen as transmission fluid temperature rises.
- Intermittent loss of forward or reverse drive: A failing unit can cause pressure bleed-off, leading to temporary loss of drive in specific ranges, particularly under load or during low-speed maneuvering.
- Audible whining or buzzing from the transmission: Worn internal bores create turbulence and cavitation, producing a distinct high-pitched noise that increases with engine RPM.
- Fluid contamination with metallic particles: Degradation of the component’s hardened surfaces sheds fine metal debris into the oil, which can be detected during routine filter inspections.
Technical Specifications
| Specification | Value |
| OEM Part Number | 4475.280.085 |
| Material | Hardened alloy steel with corrosion-resistant coating |
| Weight | 0.85 kg (1.87 lbs) |
| Dimensions (L x W x H) | 120 mm x 45 mm x 35 mm |
| Operating Pressure Range | 8–22 bar (116–319 psi) |
| Temperature Range | -40°C to +120°C |
| OEM Reference | ZF 4475.280.085 (Genuine) |
Compatibility
This part is engineered for the ZF WG 100 and WG 110 series transmissions, commonly found in medium-duty trucks, buses, and off-highway equipment. It is also compatible with the WG 180, WG 200, and WG 210 series when used in hydraulic control applications. The 4475.280.085 interfaces directly with the 4651301029: HOUSING and requires the 0634303928: O-RING for proper sealing during installation. For complete assembly, pair this component with the 4651301024: HOUSING to ensure structural alignment.
Related Components
| Part Number | Name | Function |
| 4651101007 | TRANSMISSION HOUSING | Main structural casing for gear train and valve body |
| 4651301029 | HOUSING | Secondary housing for hydraulic control module |
| 0634303928 | O-RING | Seals fluid passages between housing and valve body |
| 4651301024 | HOUSING | Lower housing for clutch piston assembly |
| 4651203002 | SCREEN SHEET | Fine mesh filter for hydraulic fluid debris |
| 4651303005 | SCREEN SHEET | Secondary filter screen for valve body inlet |
| 0636101032 | CAP SCREW | Fastener for securing housing sections |
| 0630361028 | SEALING CAP | Plugs unused hydraulic ports |
| 4475280060 | SCREW PLUG | Threaded plug for pressure test points |
| 0634303312 | O-RING | Seals screw plug and cap screw interfaces |
Frequently Asked Questions
Q: How do I know if my ZF WG100 needs the 4475.280.085 replaced?
A: If you experience delayed engagement when shifting from neutral to drive or reverse, combined with metallic debris in the transmission fluid, this component is likely worn. Always inspect the 4651301029: HOUSING for scoring during replacement.
Q: Can I reuse the old O-ring when installing this part?
A: No. Always replace the 0634303928: O-RING with a new one to prevent internal leaks. The O-ring is a single-use sealing element.
Q: Is the 4475.280.085 compatible with the ZF WG180 transmission?
A: Yes, it is compatible with WG180, WG200, and WG210 series when used in the hydraulic control valve body. Verify your transmission’s serial number against the 4651101007: TRANSMISSION HOUSING for exact fitment confirmation.
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Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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