Overview
The ZF 1204.318.011 COMPRESSION SPRING is a precision-engineered OEM genuine component designed for the internal clutch and shift assemblies within ZF WG100, WG130, and WG131 transmissions. This spring provides the necessary preload force to maintain consistent pressure on valve spools and clutch pistons, ensuring smooth gear engagement and hydraulic circuit integrity. The SKU 1204.318.011 is manufactured to ZF’s exacting tolerances, guaranteeing reliable return action and vibration dampening in heavy-duty industrial drivetrains. When paired with a 5838109021: DIFFERENTIAL assembly, this compression spring helps stabilize load distribution across the planetary gear set.
Symptoms of Failure
- Delayed or harsh gear engagement: A worn 1204.318.011 spring loses its compressive force, causing clutch packs to engage sluggishly or with a jarring impact, especially during low-speed maneuvers.
- Intermittent transmission slipping under load: When the spring fails to maintain adequate pressure on the valve body, hydraulic circuits bleed off, leading to power loss during acceleration or uphill operation.
- Audible rattling or clicking from the transmission housing: A broken or fatigued compression spring allows internal components to vibrate loosely, producing metallic noises that intensify with engine RPM.
- Erratic shift patterns in WG100/WG130 units: Inconsistent spring tension disrupts the timing of clutch application, causing the transmission to hunt between gears or skip ratios entirely.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 1204.318.011 |
| Type | Compression Spring (Helical) |
| Wire Diameter | 3.5 mm (estimated) |
| Outer Diameter | 22.0 mm (estimated) |
| Free Length | 45.0 mm (estimated) |
| Material | Chrome Silicon Alloy Steel (DIN 17223) |
| Surface Finish | Zinc-Nickel Plated (Corrosion Resistant) |
| Weight | 0.035 kg (estimated) |
| OEM Reference | ZF 1204.318.011 |
Compatibility
This OEM genuine compression spring is specifically validated for the following ZF transmission models: WG100, WG130, and WG131. It is also compatible with select variants of the WG180 and WG200 series where the same clutch piston return assembly is used. For differential-related applications, verify fitment with the 2095209019: DIFFERENTIAL unit. The spring works in concert with the 0750117075: TAPER ROLLER BEARING to reduce axial play in the output shaft, and it should be replaced alongside the 0631329086: SPRING PIN to ensure proper retention in the valve body bore.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 5838109021 | DIFFERENTIAL | Distributes torque between drive wheels |
| 0750117075 | TAPER ROLLER BEARING | Supports radial and axial shaft loads |
| 2095209019 | DIFFERENTIAL | Rear differential assembly for WG series |
| 0631329086 | SPRING PIN | Secures spring and valve components |
| 5838300817 | THRUST WASHER | Reduces friction between rotating parts |
| 5838300682 | DIFFERENTIAL AXLE | Carries differential gear assembly |
| 5838300811 | THRUST WASHER | Controls axial clearance in clutch packs |
| 5841302064 | THRUST WASHER | High-load washer for planetary gears |
| 5838300812 | SEALING RING | Prevents hydraulic fluid leakage |
| 5838300137 | OUTER CLUTCH DISK | Friction surface for torque transfer |
