Overview
The ZF 0636.021.022 HEXAGON SCREW is a critical fastening component engineered for the WG180, WG200, and WG201 transmission series. This OEM genuine part secures the TRANSMISSION HOUSING assembly, ensuring precise clamping force and structural integrity under high torque loads. Designed to withstand extreme vibration and thermal cycling, the 0636.021.022 screw maintains a leak-proof seal when paired with the O-RING and THREADED BUSH. This hexagon screw is a direct replacement for worn or damaged fasteners in planetary gear systems and clutch packs.
Symptoms of Failure
- Transmission fluid seepage around the housing joint: A loose or fatigued 0636.021.022 screw can compromise the seal, leading to visible oil drips near the OUTPUT FLANGE area.
- Abnormal gear engagement noise: When this hexagon screw loses torque, the DISCONNECTION mechanism may shift, causing grinding sounds during gear changes.
- Vibration at highway speeds: A failing fastener allows micro-movement in the transmission case, transmitting resonance through the driveline.
- Intermittent pressure loss in hydraulic circuits: A cracked screw head can cause gradual pressure drops, mimicking pump failure symptoms.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 0636.021.022 |
| Thread Size | M10 x 1.5 |
| Length | 35 mm |
| Head Type | Hexagon (17 mm socket) |
| Material | Alloy steel, zinc-plated |
| Tensile Strength | 10.9 grade |
| Weight | 0.04 kg |
| OEM Reference | ZF 0636.021.022 |
Compatibility
This hexagon screw is specifically designed for ZF WG180, WG200, and WG201 series transmissions. It is commonly used in construction vehicles, agricultural tractors, and material handlers. The 0636.021.022 replaces the older HEXAGON SCREW variant (0636020211) with improved thread geometry. Always verify thread pitch and length against your TYPE PLATE before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105475 | DISCONNECTION | Engages/disengages PTO shaft |
| 4642303097 | OUTPUT FLANGE | Connects transmission to driveshaft |
| 0636020211 | HEXAGON SCREW | Earlier version of 0636.021.022 |
| 4644101134 | TRANSMISSION HOUSING | Main structural casing |
| 4644301349 | HOUSING | Secondary cover assembly |
| 0730365125 | TYPE PLATE | Identification tag for model specs |
| 0631311009 | GROOVED STUD | Alignment dowel for housing |
| 0636305019 | SCREW PLUG | Seals oil passages |
| 4644301247 | THREADED BUSH | Reinforced insert for screw |
| 0634303485 | O-RING | Hydraulic seal for housing |
