Overview
This OEM genuine ZF 4657.025.105 component is a critical internal actuation and sealing element specifically engineered for the WG 190 Series transmission. It functions as a precision-machined guide sleeve and pressure regulator, ensuring consistent hydraulic flow to the clutch packs during gear engagement. The SKU 4657.025.105 sits within the valve body assembly, directly interfacing with the main housing to modulate line pressure. When this part is compromised, the entire shift quality of the WG190 deteriorates, leading to harsh engagements or delayed response. For technicians rebuilding a WG190, verifying the condition of the 4657101082: TRANSMISSION HOUSING is equally critical, as warpage in that housing can accelerate wear on this sleeve.
Symptoms of Failure
- Erratic shift timing and gear slipping: When the 4657.025.105 wears, internal leakage causes clutch pack pressure to drop, resulting in “ZF WG190 slipping under load” during acceleration.
- Visible hydraulic fluid seepage around the valve body: A worn sealing surface leads to “ZF transmission oil leak at valve body” as pressurized ATF bypasses the sleeve.
- Harsh or flared 2-3 upshifts: This part directly controls the modulation of the 2-3 shift valve; failure produces a “WG190 harsh 2-3 shift” complaint.
- Delayed engagement from Neutral to Drive: Reduced line pressure causes a “ZF WG190 delay engaging drive” symptom, often misdiagnosed as a solenoid issue.
Technical Specifications
| Specification | Detail |
|---|---|
| OEM Part Number | 4657.025.105 |
| Material | Hardened alloy steel with nitrided bore |
| Outer Diameter | 32.5 mm |
| Inner Diameter | 18.0 mm |
| Length | 74.2 mm |
| Weight | 0.185 kg |
| OEM Reference | ZF 4657.025.105 (Genuine) |
Compatibility
This part is designed for the ZF WG 190 Series, but it also fits the WG180 and WG200 variants due to shared valve body architecture. It is a direct replacement for earlier revision 4657.025.104. Always inspect the 4657201166: HOUS.FRONT SECT and 4657201170: HOUSING REAR PART for scoring when replacing this sleeve. In WG200 applications, the 4657298102: HOUSING REAR SECTION must also be checked for alignment tolerances.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101082 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657201166 | HOUS.FRONT SECT | Front section of transmission housing |
| 4657201170 | HOUSING REAR PART | Rear housing segment for output shaft |
| 4657298102 | HOUSING REAR SECTION | End cap housing for rear bearing support |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing mating |
| 0636100801 | CAP SCREW | M10 fastener for valve body retention |
| 4656301148 | FIXING PLATE | Locating plate for solenoid harness |
| 4657301032 | SCREEN SHEET | Fine mesh filter for valve body inlet |
| 4657301033 | SCREEN SHEET | Secondary filter for lube circuit |
| 0636100803 | CAP SCREW | M8 bolt for housing section clamping |
Frequently Asked Questions
Q: Can I reuse the old sealing rings when installing the 4657.025.105?
A: No. This part relies on a precision interference fit. Always replace all O-rings and Teflon seals in the valve body bore when installing this sleeve to prevent “ZF WG190 internal leakage” issues.
Q: Does this part require special tooling for installation?
A: Yes. A depth micrometer and a sleeve driver tool are required to seat the 4657.025.105 to a depth of 12.5 mm below the valve body face. Improper depth will cause “ZF transmission shift flare” immediately.
Q: How does this part differ from the 4657.025.104?
A: The .105 revision has a hardened inner bore coating to resist wear from contaminated fluid. It is backward compatible with all WG190, WG180, and WG200 transmissions.
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Phone: +86 158 2286 3467 |
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