Overview
The ZF 0769.123.905 SUN GEAR is a critical planetary component engineered for the WG100, WG130, and WG131 transmission series. This OEM genuine part transfers torque from the input shaft to the planetary gear set, directly influencing gear ratio stability and load distribution. The SKU 0769.123.905 sits centrally within the gear train, meshing with planetary pinions to enable smooth power flow under high-stress industrial applications. When paired with a robust HOUSING (4108101174) and a precisely machined HOUSING (4108201298), this sun gear ensures concentric alignment and minimal backlash during heavy-duty cycles.
Symptoms of Failure
- Transmission gear slipping under load: Worn teeth on the sun gear cause intermittent engagement, leading to power loss during acceleration or uphill operation.
- Metallic grinding noise from the planetary section: Pitting or spalling on the gear face produces a distinct whine or grind, especially in lower gears.
- Oil contamination with metallic debris: As the sun gear degrades, fine steel particles circulate through the system, often detected during routine oil changes or when inspecting the OIL LEVEL GAGE (0501225852).
- Erratic shift timing or harsh engagement: Excessive wear alters the planetary gear set’s rotational balance, confusing hydraulic control modules and causing delayed or jarring shifts.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 0769.123.905 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Outside Diameter | 98.4 mm (3.87 in) |
| Inner Bore Diameter | 32.0 mm (1.26 in) |
| Face Width | 28.5 mm (1.12 in) |
| Number of Teeth | 24 (standard involute profile) |
| Weight | 0.85 kg (1.87 lbs) |
| OEM Reference | ZF 0769.123.905 |
| Heat Treatment | Carburized & tempered to HRC 58-62 |
Compatibility
This sun gear is factory-specified for the ZF WG100, WG130, and WG131 off-highway transmissions. It also fits select WG180 and WG200 variants when used with the correct planetary carrier assembly. Always verify the tooth count and bore dimensions against your existing gear. For proper sealing during installation, pair this component with a new SEALING RING (0501325471) to prevent fluid bypass around the shaft.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4108101174 | HOUSING | Encloses the planetary gear set and supports bearing journals |
| 4108201298 | HOUSING | Secondary housing for clutch pack and valve body alignment |
| 0501225852 | OIL LEVEL GAGE | Provides accurate fluid level measurement for lubrication |
| 0501325471 | SEALING RING | Prevents oil leakage between rotating and stationary components |
| 0730365308 | TYPE PLATE | Identification plate with transmission serial and model data |
| 4108301475 | INPUT SHAFT | Transfers engine torque directly to the sun gear hub |
| 0750116982 | BALL BEARING | Supports radial loads on the input shaft and sun gear assembly |
| 0630502039 | RETAINING RING | Secures the sun gear axially within the carrier |
| 0630531064 | RETAINING RING | Locks the bearing in place on the output side |
| 0636302014 | SCREW PLUG | Seals hydraulic test ports and drain passages |
ZF 0769.123.905 SUN GEAR – Gear RFQ Support
Use ZF 0769.123.905 SUN GEAR as the reference when requesting gear support. Photos, visible markings, and transmission context help reduce sourcing uncertainty.
Part-Number Summary
Use ZF number 0769.123.905 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: INPUT
Cross Reference Support
If you have an OEM number, old supplier number, or visible marking, include it with your RFQ so PartsZF can compare it with the available records.
Specification Snapshot
| ZF part number | 0769.123.905 |
|---|---|
| Normalized SKU | 0769123905 |
| Part name | SUN GEAR |
| Product category | gear |
| RFQ support | Part-number lookup and documentation review |
| Media support | Product photo or diagram review when available |
Image and Documentation Notes
Current product media status: fallback. 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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