Overview
The ZF 4656.073.020 3 WG 171 Powershift Transmission Assembly | Complete Unit is a fully integrated drop-in assembly designed for heavy-duty off-highway applications. This complete unit serves as the central power distribution hub, managing torque flow from the engine through multiple planetary gear sets. The SKU 4656.073.020 identifies a factory-matched assembly that includes the main casing, clutch packs, and hydraulic control components. It sits directly between the engine bell housing and the final drive, converting high-speed engine input into usable tractive effort. For proper sealing and structural integrity, this unit mates with the 4656101028: TRANSMISSION HOUSING and the 4656301066: HOUS.FRONT SECT to form a leak-free assembly.
Symptoms of Failure
- Erratic gear engagement under load: When the internal clutch drums or seals degrade, operators experience delayed or harsh shifting, particularly when climbing grades or carrying heavy payloads.
- Low hydraulic pressure and sluggish response: Worn valve bodies or scored pistons cause a gradual drop in system pressure, leading to creeping movement or failure to hold a selected gear.
- External oil seepage from main case joints: Cracks in the main housing or failed gaskets allow transmission fluid to escape, often visible as drips near the bell housing or around the 4656201015: SCREEN SHEET area.
- Metallic debris in the oil pan: Advanced wear of planetary gears or thrust washers produces fine metal particles that clog the 4656301037: TUBE and reduce lubrication flow.
Technical Specifications
| Parameter | Value |
|---|---|
| Assembly Weight (dry) | 185 kg (408 lbs) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Primary Material | High-strength cast iron (GGG-40) with steel alloy internals |
| OEM Reference | ZF 4656.073.020 (3 WG 171) |
| Max Input Torque | 1,200 Nm |
| Hydraulic Pressure Range | 16–22 bar |
| Associated Seal | 0634313514: O-RING |
| Fastener Kit | 0636100803: CAP SCREW (M12x1.75) |
Compatibility
This complete unit is engineered for the ZF WG 171 series powershift transmissions. It is directly compatible with the WG 171, WG 180, and WG 200 models used in construction loaders, forklifts, and agricultural tractors. The assembly also fits select variants of the WG 150 and WG 220 when paired with the correct 4656301042: HOUSING REAR PART. Always verify the bell housing pattern and input shaft spline count before installation. Additional alignment components such as the 0631306816: CYLINDRICAL PIN and 0636100801: CAP SCREW are required for proper dowel alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101028 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4656301066 | HOUS.FRONT SECT | Front section housing input shaft and pump drive |
| 4656201015 | SCREEN SHEET | Fine mesh filter for hydraulic oil return |
| 4656301037 | TUBE | Oil delivery tube for clutch lubrication |
| 0634313514 | O-RING | Seals hydraulic passages between housing sections |
| 0636100803 | CAP SCREW | M12 fastener for main housing bolts |
| 4656301042 | HOUSING REAR PART | Rear section supporting output shaft and PTO |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing registration |
| 0636100801 | CAP SCREW | M10 fastener for front section attachment |
| 0636100160 | CAP SCREW | M16 fastener for rear housing mounting |
Frequently Asked Questions
Q: Can the ZF 4656.073.020 be installed without removing the entire drivetrain?
A: While it is a complete unit, we recommend removing the transmission from the vehicle for safe handling. The assembly weighs over 180 kg and requires precise alignment with the TRANSMISSION HOUSING to avoid seal damage.
Q: What is the typical service life of this assembly under normal operating conditions?
A: With proper maintenance and clean hydraulic fluid, the 3 WG 171 unit typically lasts 8,000–12,000 hours before requiring internal overhaul. Regular replacement of the O-RING and SCREEN SHEET extends service intervals.
Q: Does this complete unit include the necessary fasteners and seals?
A: The assembly is supplied as a bare unit. You will need to order the CAP SCREW kit and CYLINDRICAL PIN separately to complete the installation.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
Request a Quote →
