ZF 4644.199.912 LOOSE PARTS for WG200 | OEM Genuine Part

Overview

The ZF 4644.199.912 LOOSE PARTS kit is a critical service assembly designed for the WG 200 series transmission. This OEM genuine part contains the essential fasteners, seals, and small hardware required to secure internal components during a rebuild or major repair. Specifically, it interfaces with the TRANSMISSION HOUSING to ensure proper clamping force and leak-free operation. The SKU 4644.199.912 is often ordered alongside a DISCONNECTION kit to complete a full overhaul of the valve body area. Without this hardware, the transmission cannot maintain hydraulic pressure or structural integrity.

Symptoms of Failure

• Oil leaks at the housing seam: When the loose parts (bolts and sealing washers) degrade, you will notice fluid weeping from the joint between the transmission housing and the OUTPUT FLANGE. This is a common failure in high-mileage WG200 units.
• Gear slipping under load: Worn or missing fasteners from this kit can cause internal clearance shifts, leading to clutch pack slippage during torque converter lockup.
• Vibration at the bell housing: Loose hardware in the 4644.199.912 set can result in a resonant vibration that is most noticeable at highway speeds (50-65 mph).
• Intermittent no-shift conditions: If a HEXAGON SCREW from this kit backs out, it can obstruct the shift valve travel, causing the transmission to stick in one gear.

Technical Specifications

Compatibility

This LOOSE PARTS kit is primarily engineered for the ZF WG200 series transmissions used in medium-duty trucks and buses. It also fits the WG180 variant when used with the appropriate OUTPUT FLANGE. The kit is not compatible with the older WG120 series without additional adapter hardware. Always verify your transmission model number before ordering. The 4644.199.912 replaces the earlier 4644.198.912 revision and includes upgraded corrosion-resistant plating on all HEXAGON SCREW components.

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