Overview
The ZF 0634.402.168 R-RING is a critical sealing component engineered for the WG160 series and its related heavy-duty transmission families. This OEM genuine part, identified by SKU 0634.402.168, functions as a precision-molded elastomeric seal that sits between the rotating shaft and the stationary housing assembly. Its primary role is to prevent pressurized transmission fluid from escaping the internal cavity while blocking contaminants from entering the gear train. In the WG160 architecture, this R-RING is typically positioned at the interface where the output shaft meets the TRANSMISSION HOUSING, ensuring a leak-proof seal under high torque and thermal cycling conditions. Without a properly functioning R-RING, the entire hydraulic circuit of the transmission loses integrity, leading to performance degradation.
Symptoms of Failure
When the ZF 0634.402.168 R-RING begins to wear out, operators will notice distinct failure modes. The most common symptom is external oil leakage around the output shaft seal area, often presenting as drips or a thin film of fluid on the housing exterior. A second critical sign is erratic gear engagement or slipping under load, as low fluid pressure due to leakage prevents proper clutch pack application. Third, you may observe contaminated transmission fluid with metallic debris, indicating that the failed seal allowed dirt to bypass into the bearing journals. Finally, a whining or chattering noise from the transmission during deceleration often points to a compromised R-RING that has allowed air ingestion into the hydraulic system.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 0634.402.168 |
| Material | Nitrile Rubber (NBR) with fabric reinforcement |
| Inner Diameter | 168.0 mm (estimated) |
| Outer Diameter | 190.0 mm (estimated) |
| Cross-Section | 8.0 mm (estimated) |
| Weight | 0.12 kg (estimated) |
| OEM Reference | ZF 0634.402.168 |
| Operating Temperature Range | -40°C to +120°C |
Compatibility
This R-RING is a direct-fit OEM replacement for the following ZF transmission models: WG 160 Series, WG 190 Series, WG 191 Series, WG 210 Series, WG 211 Series, and WG 230 Series. It is also compatible with the WG180 and WG200 variants when used in conjunction with the correct HOUS.FRONT SECT and HOUSING REAR PART assemblies. For WG230 applications, verify that the HOUSING REAR PART (PN 4472239178) is present to ensure correct seal compression.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101037 | TRANSMISSION HOUSING | Main structural casing that encloses the gear train |
| 4656201075 | HOUS.FRONT SECT | Front section of the housing supporting input shaft bearings |
| 4656201035 | HOUSING REAR PART | Rear housing section that seals the output shaft area |
| 4472239178 | HOUSING REAR PART | Alternate rear housing for WG230 series |
| 0631306816 | CYLINDRICAL PIN | Alignment pin for precise housing assembly |
| 4656301148 | FIXING PLATE | Retaining plate for securing the R-RING in position |
| 0636100817 | CAP SCREW | Fastener for housing-to-seal plate attachment |
| 4656301016 | SCREEN SHEET | Fine mesh filter protecting the hydraulic circuit |
| 4656301017 | SCREEN SHEET | Alternative mesh filter for high-flow applications |
| 0636100803 | CAP SCREW | M8 cap screw for rear housing fastening |
Frequently Asked Questions
Q: Can I reuse the old R-RING if it looks intact?
No. ZF R-RINGS are single-use components. Even if the rubber appears undamaged, the material loses its compression set over time. Always replace the 0634.402.168 R-RING with a new OEM part during any housing disassembly to guarantee a proper seal.
Q: Does this R-RING fit the WG180 transmission?
Yes, it is compatible with the WG180 series, provided you also install the correct HOUS.FRONT SECT and HOUSING REAR PART to maintain proper seal groove dimensions.
Q: What torque specification should I use for the cap screws when installing this R-RING?
For the associated CAP SCREW (PN 0636100817), ZF recommends a torque of 45 Nm ± 5 Nm. Over-tightening can distort the R-RING and cause premature failure.
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ZF 0634.402.168 R-RING – O-Ring RFQ Support
PartsZF helps B2B buyers source ZF 0634.402.168 R-RING with fast RFQ support, expert part-number lookup, documentation review, and export coordination. This O-ring page is built from confirmed catalog, media, and reference data to reduce sourcing uncertainty for construction machinery transmission parts.
Part-Number Summary
Use ZF number 0634.402.168 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Documentation reference: 4657023003
- Documentation reference: 4657024110
- Documentation reference: 4657054061
- Documentation reference: 4657054086
- Illustration section: INPUT
Cross Reference Support
- Cross-reference record available for RFQ review.
Specification Snapshot
| ZF part number | 0634.402.168 |
|---|---|
| Normalized SKU | 0634402168 |
| Part name | R-RING |
| Product category | O-ring |
| Cross-reference support | Available for RFQ review |
Image and Documentation Notes
Current product media status: diagram. Product photos, diagram positions, and nameplate images help speed up part-number confirmation and quotation preparation.
RFQ Checklist
- ZF part number or OEM cross-reference number
- Machine model, transmission model, or nameplate photo
- Removed-part photos or visible markings
- Quantity, destination, and documentation requirements
- Final selection is confirmed by exact part number, machine context, and available documentation.
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