Overview
The ZF 4651.303.022 COVER is a critical sealing and structural component engineered specifically for the WG 100 and WG 110 transmission series. This OEM genuine part, identified by SKU 4651.303.022, mounts directly onto the transmission housing to enclose the valve body and hydraulic control assembly. It serves as a protective barrier against contaminants while maintaining internal oil pressure necessary for proper clutch engagement and gear selection. Precision-machined from high-grade aluminum alloy, this cover ensures a leak-free interface with the TRANSMISSION HOUSING and the HOUSING assembly, forming an integral part of the transmission’s hydraulic circuit.
Symptoms of Failure
- External oil seepage around the cover perimeter: A worn or warped 4651.303.022 COVER often leads to visible fluid leaks at the mating surface, especially after thermal cycling. This is a common long-tail search query for “ZF WG100 cover oil leak repair.”
- Erratic shifting or delayed engagement: When the cover loses its seal, hydraulic pressure drops, causing gear slipping or harsh shifts. Technicians frequently search for “WG110 transmission slipping after cover replacement.”
- Contaminated transmission fluid: A cracked cover allows dirt and moisture ingress, leading to sludge buildup. This symptom triggers searches like “dirty ATF fluid ZF WG100 cover failure.”
- Increased operating noise from the valve body: Loss of structural rigidity in the cover can amplify hydraulic chatter, a symptom often queried as “ZF transmission whining noise cover issue.”
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4651.303.022 |
| Material | Die-cast aluminum alloy (A380) |
| Overall Length | 285 mm |
| Overall Width | 195 mm |
| Overall Height | 45 mm |
| Weight | 1.2 kg |
| OEM Reference | ZF 4651.303.022 |
| Sealing Surface Finish | Ra 0.8 µm |
| Bolt Torque Specification | 25 Nm |
Compatibility
This ZF 4651.303.022 COVER is primarily designed for the WG 100 and WG 110 transmission models. Based on its mounting pattern and hydraulic port configuration, it is also compatible with the WG 180 and WG 200 series when used with the appropriate O-RING seal kit. For installations on the WG 120 and WG 150 variants, verify compatibility with the HOUSING assembly to ensure proper alignment of the dowel pins and bolt holes.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4651101009 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4651301025 | HOUSING | Secondary housing for valve body |
| 0634303928 | O-RING | Seal between cover and housing |
| 4651301031 | HOUSING | Alternate housing for WG200 series |
| 4651203002 | SCREEN SHEET | Filter mesh for hydraulic fluid |
| 4651303005 | SCREEN SHEET | Secondary filter screen |
| 0636101032 | CAP SCREW | Fastener for cover mounting |
| 0630361028 | SEALING CAP | Port protection cap |
| 4475280060 | SCREW PLUG | Threaded plug for oil passages |
| 0634303312 | O-RING | Seal for screw plug |
