Overview
The ZF 6073.015.120 EST 37 A for WG160 is a critical electro-hydraulic control unit that governs shift timing and pressure modulation within the WG 160 series transmission. This OEM genuine part, identified by SKU 6073.015.120, sits directly atop the main valve body assembly and interfaces with the TRANSMISSION HOUSING to direct oil flow for clutch engagement. As the primary electronic interface for gear selection, it converts solenoid signals into precise hydraulic actions, ensuring smooth power delivery under heavy loads. Without this component, the transmission cannot execute commanded shifts, making it indispensable for operational reliability in commercial vehicles.
Symptoms of Failure
- Erratic or delayed shifting under load: When the EST 37 A wears, you may experience harsh engagement or a noticeable lag between gear changes, particularly when climbing grades or hauling maximum payloads.
- Intermittent loss of forward or reverse gears: A failing unit can cause the transmission to suddenly drop into neutral, requiring a full system reset to regain drive.
- Hydraulic fluid contamination from internal wear: Debris from degraded solenoids or seals can circulate through the system, leading to clogged SCREEN SHEET filters and accelerated damage to adjacent components.
- Persistent diagnostic trouble codes (DTCs) for solenoid circuits: The control module will log faults related to open or shorted circuits within the EST assembly, often accompanied by a check-transmission warning light.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 6073.015.120 |
| Designation | EST 37 A (Electro-Hydraulic Shift Unit) |
| Material | Die-cast aluminum housing with stainless steel solenoids |
| Weight | 3.2 kg (7.05 lbs) |
| Operating Voltage | 24V DC (nominal) |
| Seal Type | Nitrile rubber O-rings (included) |
| Torque Specs | Mounting bolts: 25 Nm ± 2 Nm |
| Compatible Housing | HOUS.FRONT SECT and HOUSING REAR PART |
Compatibility
This genuine ZF 6073.015.120 unit is engineered primarily for the WG 160 series, but it also cross-fits select variants in the WG180 and WG200 families that share the same valve body architecture. It is not compatible with older WG120 or WG150 models without adapter plates. For proper installation, the unit must be paired with a HOUSING REAR SECTION that matches the solenoid port configuration. Always verify your transmission serial number against ZF’s application guide before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101055 | TRANSMISSION HOUSING | Main structural casing for gear and shaft assembly |
| 4656201075 | HOUS.FRONT SECT | Forward section housing the torque converter |
| 4656201076 | HOUSING REAR PART | Rear casing supporting output shaft bearings |
| 4656298047 | HOUSING REAR SECTION | Extended rear housing for PTO mounting |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing mating surfaces |
| 4656301148 | FIXING PLATE | Retains valve body to transmission housing |
| 0636100817 | CAP SCREW | M10 bolt for securing housing sections |
| 4656301016 | SCREEN SHEET | Fine mesh filter for hydraulic circuit |
| 4656301017 | SCREEN SHEET | Coarse mesh pre-filter for sump pickup |
| 0636100803 | CAP SCREW | M8 bolt for valve body attachment |
Frequently Asked Questions
Q: Can I replace the ZF 6073.015.120 without removing the transmission from the vehicle?
A: Yes, in most applications the EST unit is accessible after removing the transmission pan and lower valve body cover. However, you must disconnect the battery and relieve hydraulic pressure before unbolting the unit.
Q: How do I know if my WG160 requires the EST 37 A or an earlier revision?
A: Check the solenoid connector shape—the EST 37 A uses a rectangular 12-pin Deutsch connector. Earlier revisions use a round 8-pin connector. The SKU 6073.015.120 is stamped on the aluminum tag riveted to the unit.
Q: Will a failed EST 37 A cause damage to the transmission housing?
A: Yes, if internal debris from a seized solenoid enters the hydraulic circuit, it can score the TRANSMISSION HOUSING bores and clog the SCREEN SHEET filters. We recommend replacing the unit at the first sign of erratic shifting to avoid costly housing repairs.
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Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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