Overview
The ZF 0730.308.121 SNAP RING is a precision-engineered retaining component designed for the WG190 and WG210 series transmissions. This OEM genuine part (SKU: 0730.308.121) functions as a critical axial locking mechanism, securing internal assemblies such as planetary gear sets and bearing packs within the transmission housing. Positioned inside the main casing, it prevents lateral movement of shafts and gears under high torque loads. Without this snap ring, the entire rotating assembly can shift, leading to catastrophic internal damage. It is a small but indispensable element in the TRANSMISSION HOUSING structure, ensuring that all components remain in their designated positions during operation.
Symptoms of Failure
- Transmission oil leaks from the bell housing area: When the snap ring fatigues or breaks, the internal components shift, causing seals to misalign and allowing fluid to escape. This is a common symptom in WG210 units with high mileage.
- Gear slipping under load: A worn 0730.308.121 snap ring cannot hold the planetary carrier in place, resulting in intermittent power loss during acceleration. Drivers often report a “clunking” sensation when shifting between gears.
- Unusual metallic rattling from the transmission case: As the snap ring loses tension, loose components inside the HOUS.FRONT SECT create a distinct rattling noise, especially at idle or low RPM.
- Hard shifting or delayed engagement: A failed snap ring allows axial play in the shaft assembly, disrupting hydraulic pressure regulation and causing harsh or delayed gear engagement.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 0730.308.121 |
| Material | Spring Steel (Carbon Alloy) |
| Inner Diameter | Approx. 120 mm |
| Outer Diameter | Approx. 130 mm |
| Thickness | 3.5 mm |
| Weight | ~45 grams |
| OEM Reference | ZF 0730.308.121 |
| Finish | Zinc-plated (corrosion resistant) |
Compatibility
This snap ring is specifically engineered for ZF off-highway and industrial transmissions. It is a direct fit for the following models: WG180, WG190, WG200, WG210, BP 210, and BP 230 series. It is also compatible with certain WG150 variants when used in conjunction with the HOUSING REAR PART and HOUSING REAR SECTION. Always verify your transmission serial number before installation to ensure proper fitment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 0631306816 | CYLINDRICAL PIN | Alignment and positioning of housing sections |
| 0636100801 | CAP SCREW | Secures housing flanges |
| 4681301015 | FIXING PLATE | Locks bearing assemblies in place |
| 4681301016 | SCREEN SHEET | Filters debris from hydraulic fluid |
| 4681301017 | SCREEN SHEET | Secondary filtration for oil return |
| 0636100803 | CAP SCREW | Fastener for rear housing section |
Frequently Asked Questions
Q: Can I reuse the old snap ring during a rebuild?
A: No. The 0730.308.121 snap ring is a single-use component due to its spring-tension design. Reusing it risks failure under load, which can damage the TRANSMISSION HOUSING and internal gears.
Q: How do I know if this snap ring fits my WG190 transmission?
A: Check the groove diameter inside your housing. This snap ring fits housings with an inner groove diameter of 120 mm. It is compatible with all WG190 and WG210 series units produced after 2005.
Q: What tools are needed for installation?
A: You will need snap ring pliers with 90-degree tips and a soft-faced mallet. Ensure the ring is fully seated in the groove before assembling the HOUS.FRONT SECT or rear sections.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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