Overview
The ZF 4644.036.200 6 WG 201 Powershift Transmission Assembly | Complete Unit is a fully assembled, drop-in replacement designed for heavy-duty off-highway machinery. This complete unit integrates the torque converter, planetary gear sets, and hydraulic control system into a single, pre-tested assembly. As the core of the WG 201 series, it manages power distribution from the engine to the driveline, enabling seamless clutch engagement under load. The SKU 4644.036.200 denotes a factory-specification unit with hardened steel shafts and reinforced clutch packs, ensuring longevity in construction and mining applications.
Symptoms of Failure
When the ZF 4644.036.200 assembly begins to degrade, operators will notice distinct operational issues. Watch for these specific failure indicators:
- Erratic gear engagement under load: The transmission hesitates or clunks when shifting from forward to reverse, often accompanied by a momentary loss of power. This points to worn clutch discs within the unit.
- External oil seepage at the bell housing: Hydraulic fluid leaking from the converter housing or output shaft seal indicates degraded O-rings or a cracked housing, leading to low pressure and slipping.
- Delayed forward/reverse shuttle response: A lag of 2-3 seconds when engaging the direction lever suggests internal valve body wear or a failing torque converter stator.
- Overheating during low-speed operation: If the transmission temperature spikes above 120°C (248°F) during dozing or loading cycles, the pump or cooler bypass within the assembly is likely compromised.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4644.036.200 |
| Series | WG 201 (6-speed powershift) |
| Overall Length | 785 mm (30.9 in) |
| Dry Weight | 385 kg (849 lbs) |
| Input Torque Capacity | 2,100 Nm (1,549 lb-ft) |
| Housing Material | High-tensile cast iron (GGG-40) |
| Clutch Pack Material | Sintered bronze on steel |
| Hydraulic Pressure Range | 18–22 bar (261–319 psi) |
Compatibility
This complete unit is engineered for the ZF WG 201 series, but its mounting pattern and spline count allow direct fitment into several legacy and current models. It is a direct replacement for the following ZF transmission platforms:
- WG 180 (4-speed variants with adapter plate)
- WG 200 (standard 6-speed, non-ECU controlled)
- WG 201 (all sub-variants, including 6 WG 201)
- WG 211 (early production units with mechanical shift)
Commonly found in Case IH (Steiger 400 series), New Holland (FR9000 foragers), and Volvo (L220 wheel loaders) equipment. Always verify bell housing bolt pattern and PTO configuration before installation.
