Overview
The ZF 4656.073.004 3 WG 171 Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly integrates the main gear cluster, clutch packs, and hydraulic control elements into a single, ready-to-install package. As a core component of the WG 171 series, it manages torque distribution across multiple speeds under high load. The SKU 4656.073.004 is the direct replacement for worn or failed assemblies, ensuring that the internal clearances and clutch timing are restored to OEM specifications. This unit sits between the torque converter and the output driveline, and its integrity is critical for maintaining consistent power flow in graders, loaders, and industrial tractors.
Symptoms of Failure
- Erratic gear engagement or slipping under load: When the internal clutch discs or seals wear, the assembly fails to hold pressure, causing the machine to hesitate or lose drive power when climbing grades or pushing material.
- Delayed or harsh shifting between ranges: A failing unit often produces a noticeable lag when shifting from forward to reverse, or a jarring engagement that indicates worn valve bodies or piston seals within the 4656.073.004.
- Contaminated transmission fluid with metallic debris: Internal wear of bearings or gear teeth generates fine metal particles that appear in the oil filter or sump magnet, signaling imminent failure of the rotating assembly.
- External oil leaks at the housing mating surfaces: Cracks or warpage in the main casing allow hydraulic fluid to escape, often pooling around the bell housing or output flange area.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 4656.073.004 |
| Assembly Type | 3 WG 171 Powershift Transmission (Complete Unit) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | High-strength cast iron (GGG-40) |
| OEM Reference | ZF WG 171 Series |
| Sealing Kit Reference | 0634313514 (O-Ring) |
| Fastener Torque Spec | Use 0636100803 (Cap Screw) at 120 Nm |
Compatibility
This complete assembly is engineered for the ZF WG 171 transmission series. It is directly compatible with models such as the WG 171, WG 180, and WG 200 when used in their standard power-shift configurations. The 4656.073.004 unit also fits select variants of the WG 150 series that share the same bell housing bolt pattern and input shaft spline count. Always verify the serial number of your existing transmission against the ZF parts catalog to confirm fitment for your specific vehicle model (e.g., Volvo G-Series graders or Case 800-series loaders).
Installation Context
During a full transmission rebuild, the 4656.073.004 assembly is mounted directly into the TRANSMISSION HOUSING (4656101028), which provides the structural backbone. The front section of the case is sealed using the HOUS.FRONT SECT (4656301066) to protect the clutch packs from contamination. A critical lubrication component, the SCREEN SHEET (4656201015), must be installed in the oil sump to filter debris before it enters the pump. Additionally, the TUBE (4656301037) routes pressurized oil to the rear clutch pack and must be checked for cracks during assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101028 | TRANSMISSION HOUSING | Main structural casing that supports all internal components |
| 4656301066 | HOUS.FRONT SECT | Front cover section that seals the clutch area |
| 4656201015 | SCREEN SHEET | Oil filter screen that prevents debris from entering the hydraulic circuit |
| 4656301037 | TUBE | Pressurized oil delivery tube for rear clutch actuation |
| 0634313514 | O-RING | Seals hydraulic passages between housing sections |
| 0636100803 | CAP SCREW | High-tensile fastener for housing assembly |
| 4656301042 | HOUSING REAR PART | Rear casing section that supports output shaft bearings |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for precise housing registration |
| 0636100801 | CAP SCREW | Fastener for securing the valve body cover |
| 0636100160 | CAP SCREW | M10 bolt for oil pan attachment |
Frequently Asked Questions
Q: Can the 4656.073.004 assembly be rebuilt, or must it be replaced as a unit?
A: While individual clutch packs and seals can be serviced, the 4656.073.004 is a balanced assembly. ZF recommends replacement as a complete unit to avoid mismatched wear patterns that cause premature failure.
Q: What is the typical service life of this transmission assembly under normal operating conditions?
A: In heavy equipment applications with proper maintenance (oil changes every 1,000 hours), the 3 WG 171 assembly typically lasts 8,000 to 12,000 hours before requiring replacement.
Q: Does this part include the torque converter?
A: No. The 4656.073.004 is the powershift transmission assembly only. The torque converter is a separate component and must be ordered independently if needed.
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Phone: +86 158 2286 3467 |
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