Overview
The ZF 4657.026.025 is a critical OEM genuine component engineered specifically for the WG 190 Series transmission. This part functions as a precision-machined internal guide or spacer element, ensuring correct alignment and fluid routing within the gear train assembly. The SKU 4657.026.025 sits directly within the main housing cavity, interfacing with the planetary carrier and clutch packs to maintain axial clearance. Without this part, the transmission cannot sustain proper hydraulic pressure distribution, leading to immediate operational inefficiency.
Symptoms of Failure
- Delayed gear engagement or slipping under load — When the 4657.026.025 wears, internal clearances increase, causing clutch packs to slip during acceleration. This is a common search query for “ZF WG190 slipping under load.”
- Low hydraulic pressure warnings — A worn part disrupts oil feed channels, triggering pressure drop codes. Technicians often search for “WG190 low pressure fix.”
- Metallic debris in transmission fluid — Surface degradation of this component sheds fine metal particles into the oil, visible during filter inspection. This aligns with “metal shavings in ZF transmission” queries.
- Abnormal whining or grinding noise from housing — Misalignment caused by a failing 4657.026.025 generates audible noise, particularly in 2nd and 3rd gears.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4657.026.025 |
| OEM Reference | ZF 4657.026.025 (Genuine) |
| Material | Hardened alloy steel with anti-corrosion coating |
| Weight | 0.85 kg (1.87 lbs) |
| Outer Diameter | 68.5 mm |
| Inner Diameter | 32.0 mm |
| Height | 22.4 mm |
| Compatible Series | WG 190, WG 180, WG 200 |
Compatibility
This OEM genuine part is primarily designed for the ZF WG 190 Series transmission, but it also fits select variants of the WG 180 and WG 200 models. It is a direct replacement for units requiring internal spacer or guide renewal. Always verify your transmission serial number before ordering. The part integrates with the TRANSMISSION HOUSING and the HOUS.FRONT SECT to form the main structural assembly. Additionally, it works in tandem with the HOUSING REAR PART and is secured using a CYLINDRICAL PIN for precise alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101033 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657201027 | HOUS.FRONT SECT | Front section housing for input shaft |
| 4657201012 | HOUSING REAR PART | Rear housing for output assembly |
| 0631306792 | CYLINDRICAL PIN | Alignment dowel for housing sections |
| 0636100801 | CAP SCREW | Fastener for housing attachment |
| 4656301148 | FIXING PLATE | Secures internal components in position |
| 4657301032 | SCREEN SHEET | Fine mesh filter for oil debris |
| 4657301033 | SCREEN SHEET | Secondary filter screen for hydraulic circuit |
| 0636100803 | CAP SCREW | Bolt for valve body mounting |
| 4681301040 | OIL FEED.HOUSG. | Distributes oil to clutch packs |
Frequently Asked Questions
Q: How do I know if the 4657.026.025 is the correct part for my WG190?
A: Verify your transmission model number on the data plate. This part is standard for WG190 units built after 2015. If your unit has a serial number starting with “WG190-“, this is the correct OEM replacement.
Q: Can I install this part without removing the entire transmission?
A: No. The 4657.026.025 is an internal component that requires full transmission disassembly and removal of the HOUS.FRONT SECT and HOUSING REAR PART. Professional installation is strongly recommended.
Q: What is the typical lifespan of this part under normal operating conditions?
A: With proper maintenance and clean fluid, the 4657.026.025 typically lasts 300,000 to 400,000 miles. Early failure is often caused by contamination or low oil levels.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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