Overview
This complete ZF 4644.036.028 6 WG 201 Powershift Transmission Assembly represents a fully integrated drop-in replacement unit designed for heavy-duty off-highway applications. As a core component within the WG 201 series, this assembly manages torque distribution across six forward speeds, enabling smooth clutch engagement under load. The SKU 4644.036.028 is a direct factory-spec unit, encompassing the main housing, planetary gear sets, hydraulic valve body, and integrated torque converter. It serves as the primary driveline interface between the engine and final drives in construction and agricultural machinery, ensuring precise power modulation during shifting cycles.
Symptoms of Failure
When this powershift transmission assembly begins to degrade, operators will notice distinct operational anomalies. Common failure indicators include:
- Delayed or harsh gear engagement — A pronounced lag when shifting from neutral to forward or reverse, often accompanied by a jarring clunk, indicating worn clutch packs or degraded hydraulic pressure within the 4644.036.028 unit.
- Progressive oil seepage at housing seams — Visible fluid accumulation around the main case gasket or output shaft seal, typically caused by thermal cycling fatigue or seal hardening in the WG 201 series assembly.
- Intermittent gear slippage under load — A sudden loss of tractive effort during uphill travel or when pushing heavy material, pointing to worn friction discs or a failing torque converter stator within the complete unit.
- Unusual whining or grinding noises — High-pitched metallic sounds emanating from the transmission bell housing, often linked to bearing fatigue or planetary gear damage inside the 4644.036.028 assembly.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 4644.036.028 |
| Assembly Type | Complete Powershift Transmission |
| Series | WG 201 |
| Number of Speeds | 6 Forward / 3 Reverse |
| Dry Weight (approx.) | 385 kg (849 lbs) |
| Overall Length | 720 mm |
| Overall Width | 510 mm |
| Overall Height | 580 mm |
| Primary Housing Material | High-Grade Cast Iron (GGG-40) |
| Input Torque Capacity | 1,200 Nm (885 lb-ft) |
| OEM Reference | ZF Friedrichshafen AG |
Compatibility
This complete unit is engineered for the WG 201 series but shares mounting patterns and hydraulic logic with several adjacent ZF model families. Verified compatibility includes the following transmission models:
- ZF WG 180 — Direct bolt-on compatibility with minor adapter plate variations for older production runs.
- ZF WG 200 — Fully interchangeable; identical bell housing and PTO mounting points.
- ZF WG 201 — Primary application; exact match for all internal clutch and planetary configurations.
- ZF WG 211 — Compatible with a revised valve body spacer; consult gear ratio charts for final drive matching.
Always verify the output flange configuration and shift pattern against your original equipment before installation. This assembly is not backward-compatible with the WG 150 series without significant hydraulic circuit modifications.
