Overview
The ZF 4644.004.216 4 WG 180(500) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly integrates the full gear train, clutch packs, and hydraulic control system within a single, ready-to-install package. The SKU 4644.004.216 serves as the core power transfer component in ZF’s WG 180 series, positioned between the torque converter and the final drive. It is engineered to deliver reliable, smooth shifting under extreme loads in construction, mining, and material handling equipment. When replacing this unit, it is critical to inspect the surrounding TRANSMISSION HOUSING for cracks or wear, as misalignment can compromise the new assembly’s service life.
Symptoms of Failure
- Delayed or harsh engagement: When the 4644.004.216 assembly wears, operators often report a noticeable lag between shifting and actual gear engagement, followed by a jarring clunk. This indicates internal clutch pack or seal degradation.
- Intermittent gear slipping under load: A failing unit may cause the transmission to momentarily lose power during uphill climbs or heavy digging cycles. This symptom is frequently searched as “ZF WG180 slipping under load” and points to worn friction discs.
- External oil seepage at the bell housing: Leaks originating from the assembly’s mating surface with the HOUSING are a common failure mode. This often presents as drips or a wet film around the lower perimeter, requiring immediate attention to prevent low fluid levels.
- Unusual whining or grinding noises: A high-pitched whine that changes with engine RPM, or a grinding sound during neutral-to-drive shifts, signals bearing or planetary gear failure within the 4644.004.216 assembly.
Technical Specifications
| Specification | Value |
|---|---|
| OEM Part Number | 4644.004.216 |
| Assembly Type | Complete Powershift Unit (4 WG 180(500)) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | High-Grade Cast Iron |
| Clutch Disc Material | Sintered Bronze on Steel |
| Max Input Torque | 500 Nm |
| OEM Reference | ZF 4 WG 180(500) |
Compatibility
This 4644.004.216 assembly is specifically engineered for the ZF WG 180 series, including the 4 WG 180(500) variant. It is also compatible with the WG 200 series when used with the correct adapter plate and TYPE PLATE for identification. The unit can be retrofitted into select WG 160 applications with modifications to the GROOVED STUD pattern. Always verify the bell housing bolt circle and input shaft spline count before installation. This assembly is commonly found in ZF-equipped loaders, graders, and industrial tractors from manufacturers such as Volvo, Case, and Caterpillar.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101080 | TRANSMISSION HOUSING | Encloses and supports the gear train |
| 4644301333 | HOUSING | Rear housing for output shaft support |
| 0730365125 | TYPE PLATE | Identification plate for model and serial number |
| 0631311009 | GROOVED STUD | Alignment and fastening stud for housing |
| 0636305019 | SCREW PLUG | Seals hydraulic test ports |
| 4644301247 | THREADED BUSH | Wear insert for shift linkage pivot |
| 0634303485 | O-RING | Seals housing joint against oil leaks |
| 4644106231 | SHIFT SYSTEM | Hydraulic valve body for clutch control |
| 4644306470 | GASKET | Prevents fluid seepage at cover interfaces |
| 4644306194 | COVER PLATE | Access cover for clutch pack inspection |
