Overview
The ZF 4644.036.012 6 WG 201 Powershift Transmission Assembly is a complete, factory-spec unit engineered for heavy-duty off-highway machinery. This fully assembled gearbox integrates the torque converter, clutch packs, and hydraulic control system into a single, ready-to-install package. Designed as a direct replacement for the WG 201 series, this assembly eliminates the need for piecemeal component sourcing. The SKU 4644.036.012 specifically denotes a complete unit with updated internal seals and hardened planetary gears, ensuring it meets the rigorous demands of wheel loaders, telehandlers, and industrial tractors. It sits as the primary driveline interface between the engine and the final drive, managing power distribution across six forward and three reverse gears.
Symptoms of Failure
When the ZF 4644.036.012 assembly begins to degrade, operators will notice distinct performance issues. Recognizing these signs early can prevent catastrophic drivetrain damage.
- Delayed engagement or gear slipping under load: A worn clutch pack or degraded valve body causes a hesitation when shifting from neutral to forward or reverse, often accompanied by a momentary loss of torque during uphill operation.
- External oil leaks at the bell housing or PTO cover: Deteriorated shaft seals or a cracked housing allow transmission fluid to weep, leaving visible puddles and leading to low oil pressure warnings.
- Erratic shifting or harsh engagement: Contaminated hydraulic fluid or a failing torque converter lock-up clutch results in jarring shifts, particularly when transitioning between second and third gear.
- Whining or grinding noises from the center section: Worn bearings or damaged planetary gears produce a metallic whine that increases with engine RPM, indicating internal component fatigue.
Technical Specifications
| Parameter | Value |
|---|---|
| Assembly Weight (Dry) | ~185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width (at bell housing) | 410 mm |
| Input Torque Capacity | 600 Nm (peak) |
| Housing Material | High-strength cast iron (GGG-40) |
| Clutch Plate Material | Sintered bronze on steel |
| OEM Reference | ZF 4644.036.012 (Direct) |
| Fluid Capacity | 12.5 liters (ZF TE-ML 03 spec) |
Compatibility
This complete unit is specifically engineered for the ZF WG 201 series, but its modular design allows it to serve as a direct replacement in several closely related ZF powershift models. Verify your transmission tag before ordering.
- ZF WG 180 – Compatible with minor adapter plate modifications (check bell housing bolt pattern).
- ZF WG 200 – Direct bolt-on for most WG 200 variants (pre-2010 production).
- ZF WG 201 – Primary application; full OEM fitment.
- ZF 4 WG 200 – Functional replacement for 4-speed units, though gear ratios differ slightly.
Always cross-reference your existing unit’s serial number with the 4644.036.012 suffix to confirm hydraulic port alignment and torque converter stall speed.
