Overview
The ZF 4661.002.018 4 WG 90 Powershift Transmission Assembly | Complete Unit is a fully assembled, ready-to-install core component engineered for heavy-duty off-highway machinery. This complete unit integrates the planetary gear set, clutch packs, and hydraulic control system into a single, precision-machined housing. Designed for the WG 90 Series, it serves as the central power distribution hub, converting engine torque into smooth, reliable gear shifts under extreme loads. The SKU 4661.002.018 is a direct OEM replacement, ensuring exact fitment and performance restoration for your ZF transmission.
Symptoms of Failure
When the ZF 4661.002.018 assembly begins to degrade, operators will notice distinct operational issues. Common failure symptoms include:
- Delayed or harsh gear engagement: A noticeable lag or jarring shift when moving from neutral to forward or reverse, often caused by worn clutch discs or degraded seals within the unit.
- Internal oil leaks and low pressure: Hydraulic fluid seeping from the joint between the assembly and the TRANSMISSION HOUSING, leading to slipping gears and erratic shifting behavior.
- Unusual whining or grinding noises: Metallic sounds emanating from the transmission during operation, indicating bearing wear or gear tooth damage inside the complete unit.
- Complete loss of drive in one range: The vehicle fails to move in a specific gear range (e.g., forward but not reverse), signaling internal mechanical failure of the planetary set.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number / SKU | 4661.002.018 |
| Assembly Type | Complete Powershift Unit (4 WG 90) |
| Dry Weight (approx.) | 145 kg (320 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Primary Material | High-Grade Cast Iron / Alloy Steel |
| OEM Reference | ZF 4661.002.018 |
| Seal Kit Required | O-RING (0634100633) |
| Mounting Hardware | CYLINDRICAL PIN (0631306174) |
Compatibility
This complete unit is specifically designed for the ZF WG 90 Series of powershift transmissions. It is a direct fit for models including the WG 90, WG 92, and WG 94, which are commonly found in wheel loaders, forklifts, and telescopic handlers. The assembly interfaces directly with the HOUSING II (4661301047) and the TUBE (4661301093) to complete the hydraulic circuit. Always verify your transmission model number before ordering to ensure compatibility.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101021 | TRANSMISSION HOUSING | Main structural casing for gear and shaft support |
| 4661301047 | HOUSING II | Secondary housing for clutch pack and valve body |
| 4661301093 | TUBE | Hydraulic fluid conduit between housing sections |
| 0631306174 | CYLINDRICAL PIN | Alignment and dowel pin for precise assembly |
| 0769123894 | TYPE PLATE | Identification plate with serial number |
| 0750100022 | SCREW PLUG | Seals oil passages in the housing |
| 0636302602 | SCREW PLUG | Drain or fill port plug |
| 0634100633 | O-RING | Hydraulic seal between mating surfaces |
| 4661301041 | NOZZLE | Lubrication jet for gear cooling |
| 4661301062 | NOZZLE | Secondary lubrication spray nozzle |
