ZF 4660.122.005 PRESSURE OIL PUMP for WG98 | OEM Genuine Part

Overview

The ZF 4660.122.005 PRESSURE OIL PUMP is a critical hydraulic component engineered specifically for the WG 98 series transmission family. This OEM genuine part sits directly within the transmission housing, where it draws fluid from the sump and delivers pressurized oil to the valve body, clutch packs, and torque converter. The pump maintains consistent hydraulic pressure essential for gear engagement and lubrication. As a precision-machined assembly, the SKU 4660.122.005 ensures reliable oil flow and system pressure, directly influencing shift quality and transmission longevity. When installed alongside the TRANSMISSION HOUSING and HOUSING II, this pump forms the core of the hydraulic circuit.

Symptoms of Failure

• Delayed or harsh gear engagement: A worn pressure oil pump cannot build adequate hydraulic pressure, causing noticeable hesitation when shifting from Park to Drive or Reverse.
• Low transmission oil pressure warning: Dashboard indicators or diagnostic codes (e.g., P0841) may appear as the pump fails to maintain specified pressure levels.
• Audible whining or grinding noise: Internal wear or cavitation produces a high-pitched sound from the transmission pan area, especially during cold starts.
• Oil leaks around the pump housing: Degraded seals or a cracked pump body allow fluid to escape, often pooling near the CYLINDRICAL PIN mounting points.

Technical Specifications

Compatibility

This pressure oil pump is designed for the ZF WG 98 series, which includes the WG180, WG200, and WG250 transmission models. It is also compatible with select WG 98 variants used in off-highway vehicles, buses, and heavy-duty trucks. The pump interfaces directly with the SUCTION TUBE and requires proper sealing via the O-RING (0634100317). Always verify your transmission model against the OEM parts list before installation.

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