Overview
The ZF 0730.501.670 RETAINING RING is a critical axial locking component engineered specifically for the WG 94 series of powershift transmissions. This OEM genuine part, identified by SKU 0730.501.670, secures internal assemblies—such as gear clusters and bearing packs—against the transmission housing bore. By preventing lateral movement under high torque loads, it maintains precise gear alignment and clutch pack clearance. This retaining ring interfaces directly with the TRANSMISSION HOUSING and the HOUSING II to form a rigid structural envelope. Without this ring, the entire rotating assembly risks catastrophic axial displacement.
Symptoms of Failure
- Intermittent gear slippage under load: A worn or fatigued retaining ring allows the gear stack to shift axially, causing partial disengagement of dog clutches during heavy hauling.
- Metallic grinding noises from the bell housing: When the ring loses its snap tension, gears contact the housing walls, producing a distinct scraping sound during deceleration.
- Unexplained transmission fluid contamination: A broken ring can score the housing bore, generating metallic debris that bypasses the filter and circulates through the valve body.
- Hard shifting or delayed engagement: Axial play from a compromised ring misaligns the shift rail, preventing the CYLINDRICAL PIN from seating correctly in its detent.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0730.501.670 |
| Material | Spring steel (DIN 17222), phosphate coated |
| Inner Diameter | 130.0 mm |
| Outer Diameter | 142.5 mm |
| Thickness | 3.5 mm |
| Weight | 0.045 kg |
| OEM Reference | ZF 0730.501.670 |
| Installation Torque | N/A (snap-fit only) |
Compatibility
This retaining ring is a direct-fit component for the WG 94 series of ZF powershift transmissions. It is commonly used in the following models: WG94, WG180, WG200, and WG211. These transmissions are found in heavy-duty construction equipment, including wheel loaders, graders, and dump trucks from manufacturers such as Caterpillar, Volvo, and Liebherr. Always verify the housing bore diameter against the ring’s outer dimension before installation. The TYPE PLATE on your transmission housing provides the definitive model code for cross-referencing.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101037 | TRANSMISSION HOUSING | Main structural casing for gear and shaft assembly |
| 4661301099 | HOUSING II | Secondary housing section for clutch pack retention |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for housing-to-housing registration |
| 0769123894 | TYPE PLATE | Identification plate with transmission model and serial number |
| 0750100022 | SCREW PLUG | Seals oil gallery access ports |
| 4660201008 | SCREW PLUG | Magnetic drain plug for ferrous debris collection |
| 0636100117 | SCREW PLUG | Pressure test port plug for diagnostic checks |
| 0501211384 | VALVE | Modulating valve for clutch pressure regulation |
| 0732042156 | COMPRESSION SPRING | Returns valve spool to neutral position |
| 0768409154 | SCREW PLUG | Hex socket plug for oil cooler circuit |
