Overview
The ZF 0501.326.295 SPRING is a precision-engineered OEM genuine component designed for the clutch and shift mechanism assemblies within ZF WG100, WG130, and WG131 transmissions. This spring provides the necessary tension and return force for actuating pistons and valve spools, ensuring consistent hydraulic pressure regulation. The SKU 0501.326.295 is a direct replacement part that restores original factory performance. It works in concert with the 4663101001: HOUSING to maintain proper alignment and with the 4663301025: COVER to seal the assembly against contamination.
Symptoms of Failure
- Delayed or harsh gear engagement: A fatigued spring fails to return the shift valve, causing hesitation when selecting forward or reverse.
- Intermittent clutch slip under load: Insufficient spring force reduces clamping pressure on clutch packs, leading to power loss during acceleration.
- Erratic shift timing: Worn springs create inconsistent hydraulic timing, resulting in abrupt or floating shifts.
- Transmission fluid contamination: A broken spring can shed metal fragments into the oil circuit, damaging the 0631306816: CYLINDRICAL PIN and valve body surfaces.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0501.326.295 |
| Material | Chrome-silicon alloy steel (DIN 17223) |
| Wire Diameter | 2.5 mm |
| Outer Diameter | 18.0 mm |
| Free Length | 45.0 mm |
| Weight | 0.012 kg |
| OEM Reference | ZF 0501.326.295 |
| Surface Treatment | Zinc-nickel plated (corrosion resistant) |
Compatibility
This spring is specifically engineered for ZF WG-series transmissions, including the WG100, WG130, and WG131 models. It is also compatible with certain variants of the WG180 and WG200 when used in the clutch return assembly. Always verify the spring’s free length and coil count against your existing part. The 0636100817: CAP SCREW must be torqued to specification when reinstalling the spring retainer.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4663101001 | HOUSING | Encloses the spring and valve assembly |
| 4663301025 | COVER | Seals the housing and retains lubrication |
| 0631306816 | CYLINDRICAL PIN | Aligns spring and valve components |
| 0636100817 | CAP SCREW | Secures the spring retainer to the housing |
| 4656301148 | FIXING PLATE | Prevents axial movement of the spring |
| 0636611009 | STUD | Provides threaded mounting for the cover |
| 0634303928 | O-RING | Seals the housing-to-cover interface |
| 4475280099 | SCREW PLUG | Closes hydraulic test ports |
| 0634303266 | O-RING | Seals the screw plug |
| 4475280018 | SCREW PLUG | Alternative port closure plug |
