Overview
The ZF 4644.199.251 LOOSE PARTS set is a critical OEM genuine service kit designed for the WG 180 series transmission. This assembly-specific package contains the essential fasteners, seals, and positioning components required to secure internal sub-assemblies within the transmission housing. As a loose parts kit, it ensures that all small hardware—such as bolts, washers, and locating pins—are replaced during a major overhaul, preventing premature wear caused by loose or fatigued components. The SKU 4644.199.251 is engineered to match original factory tolerances, guaranteeing a precise fit when installed alongside the 4644101080: TRANSMISSION HOUSING and the 4644301333: HOUSING.
Symptoms of Failure
When the ZF 4644.199.251 LOOSE PARTS begin to degrade or are not replaced during service, operators may notice several distinct failure modes. Transmission oil seepage at the housing joints is a common early indicator, as worn fasteners cannot maintain proper clamp load on the 4644306464: GASKET. Intermittent gear engagement or delayed shifting often occurs when loose hardware allows internal components to shift out of alignment. Abnormal metallic rattling from the bell housing suggests that retaining hardware has fatigued, permitting movement of the 4644106055: SHIFT SYSTEM. Finally, vibration during torque converter lockup can indicate that the 0631311009: GROOVED STUD has loosened, compromising the structural integrity of the assembly.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.199.251 |
| Product Type | Loose Parts Kit (Hardware Set) |
| Material Composition | Case-hardened steel / Zinc-plated alloy |
| Weight (approx.) | 0.45 kg (1.0 lb) |
| OEM Reference | ZF 4644.199.251 |
| Thread Pitch (primary bolts) | M8 x 1.25 |
| Operating Temperature Range | -40°C to +120°C |
| Surface Finish | Passivated / Corrosion-resistant |
Compatibility
This OEM genuine loose parts kit is primarily engineered for the ZF WG 180 series transmission. Based on the hardware specifications and fastener geometry, it is also compatible with the WG 200 and WG 150 series in certain applications where the 4644301247: THREADED BUSH and 0634303485: O-RING are shared. The kit is not suitable for the earlier WG 120 series without verification of the 0730365125: TYPE PLATE identification. Always cross-reference the 4642306050: COVER PLATE part number to confirm fitment before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101080 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301333 | HOUSING | Secondary housing for valve body assembly |
| 0730365125 | TYPE PLATE | Identification tag for transmission model |
| 0631311009 | GROOVED STUD | Alignment dowel for housing mating |
| 0636305019 | SCREW PLUG | Seals hydraulic test ports |
| 4644301247 | THREADED BUSH | Reinforced insert for high-torque fasteners |
| 0634303485 | O-RING | Static seal between housing sections |
| 4644106055 | SHIFT SYSTEM | Mechanical linkage for gear selection |
| 4642306050 | COVER PLATE | Access cover for clutch pack inspection |
| 4644306464 | GASKET | Sealing layer between housing faces |
