Overview
The ZF 0630.004.338 SHIM RING is a precision-engineered spacer component designed for the WG 65 series of heavy-duty automatic transmissions. This OEM genuine part plays a critical role in establishing the correct axial clearance between rotating assemblies and stationary housings within the gear train. By maintaining precise end-play tolerances, the shim ring prevents metal-on-metal contact that can lead to premature bearing wear and gear misalignment. The SKU 0630.004.338 is specifically calibrated to fit the output shaft and planetary carrier stack, ensuring that hydraulic pressure distribution remains consistent during high-torque operations. Without this thin but vital ring, the entire transmission assembly risks catastrophic internal damage under load.
Symptoms of Failure
- Oil leaks from the rear seal area: When the shim ring wears or compresses unevenly, the output shaft shifts axially, distorting the SEALING RING and allowing transmission fluid to escape.
- Gear slipping during upshifts: Incorrect shim thickness reduces clutch pack clamping force, causing the transmission to momentarily lose torque transfer between gears.
- Metallic grinding noise from the bell housing: Excessive end-play allows the planetary gears to contact the TRANSMISSION HOUSING, producing a distinct scraping sound during deceleration.
- Delayed engagement when shifting from Neutral to Drive: Worn shims alter the hydraulic valve timing, resulting in a noticeable lag before power reaches the wheels.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0630.004.338 |
| Material | Case-hardened steel (DIN 1.3505 equivalent) |
| Inner Diameter | 38.0 mm |
| Outer Diameter | 52.0 mm |
| Thickness | 0.50 mm (selective fit) |
| Weight | 12 grams |
| OEM Reference | ZF 0630.004.338 |
| Surface Finish | Ground, Ra ≤ 0.8 µm |
Compatibility
This shim ring is engineered for the ZF WG 65 series, but its dimensional profile also suits several other ZF power take-off and marine transmission models. Verified compatible transmissions include the WG65, WG120, WG180, and WG200 series. It is commonly used in retrofit kits for the 4WG-65 and 5WG-65 variants. When replacing this shim, always inspect the mating HEXAGON SCREW (M8x20) and the HEXAGON SCREW (M10x25) for thread wear, as overtightening can distort the shim ring. Additionally, the HEXAGON SCREW (M12x30) used in the clutch housing must be torqued to factory specifications to avoid crushing the shim.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101059 | TRANSMISSION HOUSING | Main structural casing that encloses all rotating components |
| 0636011038 | HEXAGON SCREW | M8 fastener securing the oil pump cover to the housing |
| 0636011118 | HEXAGON SCREW | M10 fastener for the clutch drum retention plate |
| 0636016015 | HEXAGON SCREW | M12 fastener for the output flange mounting |
| 0631306085 | CYLINDRICAL PIN | Alignment dowel for precise housing-to-cover positioning |
| 0634313118 | O-RING | Static seal between the valve body and housing |
| 0636304019 | SCREW PLUG | Sealed drain port plug for the oil pan |
| 0634801152 | SEALING RING | Dynamic shaft seal preventing fluid egress |
| 0732611049 | FILTER INSERT | High-pressure hydraulic oil filtration element |
| 0634303718 | O-RING | Seal for the cooler line adapter fitting |
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