Overview
The ZF 4657.304.002 DIFF.COVER is a critical sealing and structural component designed for the WG190 and WG210 series transmissions. This OEM genuine part encloses the differential assembly, protecting internal gears and bearings from contamination while maintaining proper oil pressure within the housing. The SKU 4657.304.002 serves as the factory-specified cover that bolts directly onto the rear of the transmission housing, ensuring a precise fit and reliable sealing under high-torque conditions. Without this cover, the differential unit would be exposed to debris and pressure loss, leading to premature wear of adjacent components such as the TRANSMISSION HOUSING and the HOUS.FRONT SECT.
Symptoms of Failure
When the ZF 4657.304.002 DIFF.COVER deteriorates, operators may notice several distinct failure indicators. Oil leaks around the differential cover gasket are the most common symptom, often appearing as drips beneath the transmission bell housing. Gear slipping or delayed engagement can occur if the cover warps, allowing differential pressure to drop. Unusual whining or grinding noises from the rear of the transmission typically signal that the cover has cracked or lost its seal, permitting metal debris to enter the gear mesh. Contaminated transmission fluid—appearing dark or containing metallic particles—is another sign that the cover’s integrity has been compromised, allowing external contaminants to mix with the oil.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4657.304.002 |
| Material | Die-cast aluminum alloy with corrosion-resistant coating |
| Weight | 1.8 kg (approx.) |
| Dimensions (L x W x H) | 280 mm x 180 mm x 45 mm |
| OEM Reference | ZF 4657.304.002 (Genuine) |
| Bolt Torque Specification | 45 Nm (M10 bolts) |
| Sealing Type | Integrated gasket groove with O-ring |
Compatibility
This DIFF.COVER is engineered for ZF’s WG series transmissions, specifically the WG190 and WG210 models. It is also compatible with the WG180 and WG200 series when used in differential configurations that share the same bolt pattern and housing geometry. The cover interfaces directly with the HOUSING REAR PART and is secured using a CYLINDRICAL PIN for precise alignment during assembly. Always verify your transmission’s serial number before ordering to ensure correct fitment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101039 | TRANSMISSION HOUSING | Main structural casing for gear sets |
| 4657201028 | HOUS.FRONT SECT | Front section housing for input shaft |
| 4657201013 | HOUSING REAR PART | Rear housing supporting output bearings |
| 0631306792 | CYLINDRICAL PIN | Alignment dowel for housing assembly |
| 0636100801 | CAP SCREW | Fastener for cover and housing joints |
| 4656301148 | FIXING PLATE | Retains cover in position |
| 4657301034 | SCREEN SHEET | Fine mesh filter for oil return |
| 4657301035 | SCREEN SHEET | Coarse mesh pre-filter |
| 0636100803 | CAP SCREW | Secondary fastener for differential cover |
| 4681301040 | OIL FEED.HOUSG. | Lubrication channel housing |
Frequently Asked Questions
Q: Can I reuse the old gasket when installing a new 4657.304.002 cover?
A: No. Always replace the gasket or O-ring with a new one to ensure a proper seal. Reusing old sealing elements can lead to immediate oil leaks and contamination of the differential assembly.
Q: What torque should I use for the cover bolts?
A: The recommended torque for the M10 bolts securing the DIFF.COVER is 45 Nm. Over-tightening can warp the cover, while under-tightening may cause fluid seepage. Use a calibrated torque wrench for best results.
Q: Is this cover compatible with the WG180 transmission?
A: Yes, the 4657.304.002 fits WG180, WG190, WG200, and WG210 models, provided the differential housing uses the same bolt pattern. Verify your transmission’s rear housing part number for confirmation.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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