Overview
The ZF 4660.306.138 COVER is a critical sealing and protective component designed for the WG 92 and WG 98 series transmissions. This OEM genuine part, identified by SKU 4660.306.138, sits on the exterior of the transmission housing, providing a secure barrier against contaminants while maintaining internal oil pressure. It interfaces directly with the 4660101023: TRANSMISSION HOUSING to ensure the integrity of the gear train environment. Precision-engineered to ZF specifications, this cover prevents debris ingress and supports the structural alignment of adjacent assemblies, making it indispensable for long-term drivetrain reliability.
Symptoms of Failure
When the ZF 4660.306.138 COVER deteriorates, operators often encounter specific performance issues. Watch for these failure indicators:
- External oil seepage around the cover perimeter – A worn gasket or cracked cover allows transmission fluid to escape, leading to low lubricant levels and potential overheating.
- Gear engagement hesitation or slipping – Loss of internal pressure due to a compromised seal can cause erratic clutch pack behavior, especially under load.
- Contamination of transmission fluid – A damaged cover permits dirt and moisture to enter the system, accelerating wear on bearings and gears.
- Unusual vibration or noise from the housing area – Loose fasteners or a warped cover can create resonance, signaling imminent failure of the 4660301058: HOUSING interface.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4660.306.138 |
| Material | Die-cast aluminum alloy (A380) |
| Weight | 1.2 kg (2.65 lbs) |
| Dimensions (L x W x H) | 210 mm x 140 mm x 45 mm |
| OEM Reference | ZF 4660.306.138 |
| Fastener Torque Spec | 25 Nm (18.4 ft-lbs) |
| Sealing Surface Finish | Ra 0.8 µm |
Compatibility
This cover is engineered for the WG 92 and WG 98 series, but it also fits select ZF transmissions that share the same housing architecture. Compatible models include the WG180, WG200, WG210, and WG250 series, where it mounts directly to the 4660101023: TRANSMISSION HOUSING. Always verify the casting number on your existing cover before installation. For secure mounting, use the 0631306174: CYLINDRICAL PIN for alignment and the 0750100022: SCREW PLUG for sealing access ports.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4660101023 | TRANSMISSION HOUSING | Main structural casing for gear assembly |
| 4660301058 | HOUSING | Secondary housing for valve body integration |
| 0631306174 | CYLINDRICAL PIN | Precision alignment dowel for cover positioning |
| 0750100022 | SCREW PLUG | Seals hydraulic test ports and drain holes |
| 4660301009 | BRACKET | Mounting support for external sensors |
| 4660221039 | TUBE | Oil supply conduit to clutch pack |
| 0636103274 | CAP SCREW | High-strength fastener for cover retention |
| 0634306185 | O-RING | Elastomeric seal for fluid-tight joint |
| 4660221041 | TUBE | Return line for lubrication circuit |
| 4660221040 | TUBE | Pressure feed tube for torque converter |
