Overview
The ZF 0634.303.422 O-RING is a precision-engineered sealing component designed for the hydraulic control circuits of ZF WG100, WG130, and WG131 transmissions. This OEM genuine part, identified by SKU 0634.303.422, creates a critical static seal between the valve body and the transmission housing, preventing pressurized ATF (Automatic Transmission Fluid) from bypassing internal passages. It is installed directly within the main control assembly, often adjacent to the 4143101009 HOUSING and the 4143301025 HOUSING, ensuring that hydraulic pressure is directed precisely to clutches and servos. Without this seal, the transmission cannot maintain the line pressure required for proper gear engagement.
Symptoms of Failure
- External ATF leaks at the valve body interface: A hardened or cracked 0634.303.422 O-RING allows fluid to seep past the mating surfaces, leaving visible drips on the transmission pan or bell housing.
- Delayed or harsh shifting between gears: When the seal fails, internal pressure drops, causing the transmission to hesitate before engaging reverse or drive, followed by abrupt shifts.
- Intermittent gear slipping under load: A compromised O-ring can cause momentary pressure loss in specific clutch circuits, resulting in the engine revving without proportional acceleration during uphill climbs or towing.
- Low transmission fluid level without visible external puddles: Internal leakage through a worn seal can redirect fluid into the torque converter housing, leading to chronic low sump levels and eventual overheating.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0634.303.422 |
| Type | Static O-Ring Seal |
| Inner Diameter (ID) | 18.0 mm (estimated) |
| Cross-Section (CS) | 2.5 mm (estimated) |
| Material | Nitrile Butadiene Rubber (NBR) / FKM |
| Hardness | Shore A 70 ± 5 |
| Weight | ~2 grams |
| OEM Reference | ZF 0634.303.422 |
| Application | Hydraulic control system seal |
Compatibility
This O-ring is specifically engineered for the ZF WG series of powershift transmissions. It is a direct fit for the following models: WG100, WG130, and WG131. It may also be applicable to certain variants of the WG180 and WG200 transmissions where the valve body uses identical port dimensions. Always verify the cross-section and groove depth before installation. When replacing this seal, it is recommended to also inspect the 0634313603 O-RING and the 4475280018 SCREW PLUG for signs of wear, as they are part of the same hydraulic circuit.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101009 | HOUSING | Main valve body housing |
| 4143301025 | HOUSING | Secondary control housing |
| 0634313603 | O-RING | Seal for adjacent hydraulic port |
| 4475280018 | SCREW PLUG | Threaded plug for pressure test port |
| 0501342341 | SUPPORT RING | Backup ring for high-pressure O-rings |
| 4143298457 | SEAL KIT | Complete gasket set for valve body |
| 0634313591 | O-RING | Seal for accumulator piston |
| 0636101068 | CAP SCREW | Fastener for housing assembly |
| 4143221013 | THROTTLE VALVE | Pressure modulation spool valve |
| 0634304484 | O-RING | Seal for throttle valve bore |
ZF 0634.303.422 O-RING – O-Ring RFQ Support
PartsZF helps B2B buyers source ZF 0634.303.422 O-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 0634.303.422 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: OUTPUT
- Illustration section: KIT REPAIR KIT
Cross Reference Support
- Cross-reference record available for RFQ review.
Specification Snapshot
| ZF part number | 0634.303.422 |
|---|---|
| Normalized SKU | 0634303422 |
| Part name | O-RING |
| Product category | O-ring |
| Cross-reference support | Available for RFQ review |
| Weight | 0.003 |
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.
Related Parts
- ZF 0634.303.280 O-RING
- ZF 0634.306.523 O-RING
- ZF 0634.306.213 O-RING
- ZF 0734.313.134 O-RING
- ZF 0634.313.728 O-RING
