ZF 4651.251.008 for WG100 | OEM Genuine Part

Overview

This OEM genuine ZF 4651.251.008 component is a critical hydraulic control element specifically engineered for the WG 100 and WG 110 series transmissions. It functions as a pressure regulation and fluid distribution interface within the valve body assembly, ensuring precise clutch engagement and torque converter lock-up. The part number 4651.251.008 is manufactured to ZF’s exacting tolerances, providing a direct replacement that restores factory shift quality and hydraulic integrity. When installed, this unit works in concert with the 4651101007: TRANSMISSION HOUSING to maintain proper oil gallery sealing and pressure containment.

Symptoms of Failure

• Erratic shift timing and harsh engagement: A worn 4651.251.008 often causes delayed or abrupt gear changes, particularly during 2-3 and 3-4 upshifts, as hydraulic pressure bleeds past degraded seals.
• Torque converter shudder under load: When this part fails, insufficient lock-up pressure leads to noticeable vibration or slipping during highway cruising, often misdiagnosed as a converter issue.
• External oil seepage near the valve body cover: Cracking or warpage of the component allows transmission fluid to escape, leaving visible drips on the bell housing or under the vehicle.
• Intermittent loss of forward or reverse gear: Severe wear can cause temporary pressure drops, resulting in a “no-move” condition that resolves after the transmission cools down.

Technical Specifications

Compatibility

This genuine ZF 4651.251.008 is designed primarily for the WG 100 and WG 110 transmission series, which are commonly found in medium-duty commercial vehicles and off-highway equipment. Based on its hydraulic control function, it is also compatible with the WG 180, WG 200, and WG 210 series when used in conjunction with the correct 4651301029: HOUSING adapter. For proper sealing during installation, always replace the 0634303928: O-RING and verify alignment with the 4651301024: HOUSING to prevent cross-threading.

Frequently Asked Questions

Q: Can I install the 4651.251.008 without removing the transmission from the vehicle?
Yes, in most applications this part is accessible after removing the transmission oil pan and valve body cover. However, you must drain the fluid and clean the mating surfaces thoroughly to avoid contamination.

Q: How do I know if my failure is caused by this part versus a solenoid issue?
If you experience erratic shifting without diagnostic trouble codes for solenoids, the 4651.251.008 is likely the culprit. A pressure test at the valve body test ports will confirm low or fluctuating pressure specific to this component.

Q: Is this part interchangeable between WG 100 and WG 110 series?
Yes, the 4651.251.008 is physically identical for both series. However, always verify the revision level against your transmission’s serial number, as late-model WG 110 units may require an updated seal kit.

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