Overview
The ZF 0637.100.200 HEXAGON NUT is a critical fastening component engineered specifically for the WG200 and WG201 series transmissions. This OEM genuine part secures the planetary carrier assembly within the gearset, ensuring precise axial retention under high-torque loads. The SKU 0637.100.200 is machined from high-strength alloy steel to withstand the extreme vibration and thermal cycling common in heavy-duty industrial applications. Without this nut, the transmission’s internal clearances cannot be maintained, leading to premature wear of adjacent assemblies such as the 4644101212: TRANSMISSION HOUSING and the 4644301221: TRANSMISSION HOUSING.
Symptoms of Failure
- Oil seepage at the output flange: A loosened 0637.100.200 nut allows the seal surface to shift, causing transmission fluid to weep past the 0634306531: O-RING.
- Intermittent gear slippage under load: When the hexagon nut loses torque, the planetary carrier can drift axially, resulting in incomplete clutch engagement and power loss during acceleration.
- Metallic rattling from the bell housing: A worn or stripped nut permits radial play in the shaft assembly, producing a distinct knocking sound that intensifies with RPM changes.
- Difficulty engaging reverse gear: Backlash caused by a failing nut directly affects the 0631311009: GROOVED STUD alignment, making reverse shifts feel notchy or unresponsive.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0637.100.200 |
| Thread Size | M30 x 1.5 (estimated) |
| Hex Width Across Flats | 46 mm |
| Material | Alloy Steel, 10.9 Grade |
| Surface Finish | Zinc-Nickel Plated |
| Weight | 0.12 kg |
| OEM Reference | ZF 0637.100.200 |
Compatibility
This hexagon nut is designed for ZF WG series transmissions, including the WG180, WG200, and WG201 models. It also fits select variants of the WG160 and WG211 where the planetary carrier uses a 30mm threaded shaft. Always verify the thread pitch against your existing 0730365067: TYPE PLATE before installation. The nut works in conjunction with the 4644303060: COVER PLATE and 4644303061: COVER PLATE to seal the final drive cavity.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101212 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301221 | TRANSMISSION HOUSING | Rear housing section for WG200 |
| 0730365067 | TYPE PLATE | Identification tag with model specs |
| 0631311009 | GROOVED STUD | Alignment dowel for clutch pack |
| 4644303060 | COVER PLATE | Seals the output shaft bore |
| 4644303061 | COVER PLATE | Alternate cover for WG201 |
| 4644221031 | SCREEN TUBE | Oil filter intake pipe |
| 0634306531 | O-RING | Static seal for housing joint |
| 0634306525 | O-RING | Dynamic seal for shaft |
| 0636305026 | SCREW PLUG | Drain/fill port closure |
