Overview
The ZF 0730.501.817 RETAINING RING is a critical axial locking component engineered specifically for the WG 94 Series transmission family. This OEM genuine part functions as a precision snap ring that secures internal gear assemblies, bearing packs, and shaft components within their designated bores. Positioned within the main gear train housing, the retaining ring prevents lateral displacement of rotating elements under high-torque conditions. The SKU 0730.501.817 is manufactured to exact ZF tolerances, ensuring a secure interference fit that maintains proper gear mesh alignment and prevents catastrophic disassembly during operation. This ring is typically installed adjacent to the 4661101037: TRANSMISSION HOUSING and the 4661301099: HOUSING II, forming a sealed containment system for the planetary gear sets.
Symptoms of Failure
When the ZF 0730.501.817 RETAINING RING fatigues or fractures, operators will notice distinct performance degradation. Watch for these specific failure indicators:
- Axial gear train clatter during deceleration – A loose retaining ring allows gear clusters to shift, producing a metallic rattling sound when the transmission coasts.
- Intermittent gear slippage under load – As the ring loses its grip, shafts can walk out of position, causing momentary loss of torque transfer in WG94-equipped vehicles.
- Transmission fluid contamination with metallic debris – A broken ring grinds against the TRANSMISSION HOUSING, shedding steel particles into the oil circuit.
- Hard shifting or delayed engagement – Misalignment from a failed ring alters clutch pack clearances, leading to harsh gear changes.
Technical Specifications
| Part Number | 0730.501.817 |
| Material | Spring steel (DIN 17222), phosphate coated |
| Inner Diameter | 85.0 mm (nominal) |
| Outer Diameter | 92.5 mm |
| Thickness | 2.5 mm |
| Weight | 18 grams |
| OEM Reference | ZF 0730.501.817 (genuine) |
| Fitment Type | Internal snap ring, DIN 472 equivalent |
Compatibility
This retaining ring is a direct replacement for the WG 94 Series transmission family. Based on its dimensional profile and application, the 0730.501.817 is compatible with the following ZF models: WG94, WG180, WG200, and WG250 series. It is also found in select Ecomat 4HP and 6HP variants where the WG94 planetary carrier assembly is used. The ring works in concert with the 0631306174: CYLINDRICAL PIN to index the gear set, and the 0769123894: TYPE PLATE for proper identification during rebuilds. Always verify your transmission serial number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101037 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4661301099 | HOUSING II | Secondary housing for clutch pack assembly |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for gear carrier positioning |
| 0769123894 | TYPE PLATE | Identification plate with transmission specs |
| 0750100022 | SCREW PLUG | Seals oil passages in valve body |
| 4660201008 | SCREW PLUG | Closes pressure test ports |
| 0636100117 | SCREW PLUG | Oil drain plug for housing |
| 0501211384 | VALVE | Modulates hydraulic pressure to clutches |
| 0732042156 | COMPRESSION SPRING | Returns valve spool to neutral position |
| 0768409154 | SCREW PLUG | High-pressure sealing plug for accumulator |
