Overview
The ZF 4644.026.292 6 WG 200(555/5) Powershift Transmission Assembly is a complete, factory-grade unit designed for heavy-duty off-highway machinery. As a core component of the WG 200 series, this assembly integrates the torque converter, planetary gear sets, and hydraulic control system into a single, ready-to-install package. The SKU 4644.026.292 specifically denotes a 6-speed forward, 1-reverse configuration with a 555/5 ratio split, optimized for loader and dozer applications requiring high torque at low speeds. This unit replaces the need for individual sub-assembly repairs, ensuring structural integrity and precise gear alignment from the outset.
Symptoms of Failure
When the ZF 4644.026.292 begins to degrade, operators typically notice distinct operational issues. Recognizing these signs early can prevent catastrophic driveline damage.
- Erratic gear engagement and clutch shudder: Worn clutch packs or valve body contamination cause delayed or harsh shifting, particularly when transitioning from forward to reverse under load.
- Internal hydraulic pressure loss: A failing pump or seal degradation leads to low line pressure, resulting in transmission slippage under heavy load and an inability to hold gear on inclines.
- Torque converter overheating: Stator clutch failure or contaminated fluid generates excessive heat, often indicated by dashboard warning lights or fluid discoloration (burnt smell).
- External oil seepage from main housing seals: Cracks in the housing or worn input/output shaft seals cause fluid to weep, leading to low oil levels and eventual gear starvation.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number / SKU | 4644.026.292 |
| Series | WG 200 (6 WG 200) |
| Configuration | 6 Forward / 1 Reverse (Powershift) |
| Dry Weight (approx.) | 485 kg (1,069 lbs) |
| Overall Length | 785 mm |
| Input Torque Capacity | 2,000 Nm (peak) |
| Housing Material | High-strength cast iron (GGG-40) |
| OEM Reference | ZF 4644.026.292 / 555/5 Ratio |
| Fluid Capacity | 38 liters (10 US gal) |
Compatibility
This complete assembly is engineered for the ZF WG 200 series transmission family. While the 4644.026.292 is a direct fit for the 6 WG 200 variant, it is also mechanically compatible with the following ZF models when using the correct bellhousing adapter kit:
- ZF WG 180 (4-speed and 6-speed variants) – requires output flange modification.
- ZF WG 200 (all 5/5 and 6/6 ratio configurations) – direct bolt-on replacement.
- ZF WG 210 (limited compatibility with torque converter housing swaps).
- ZF 4 WG 200 (older 4-speed units) – upgrade path with ECU reflash.
Always verify the input shaft spline count (typically 14-tooth for this SKU) against your existing driveline before installation. This unit is commonly used in Volvo L220G, Caterpillar 950M, and Komatsu WA380 wheel loaders.
