Overview
The ZF 5838.300.721 Axle Bevel Gear is a critical power-transfer component engineered for the WG100, WG130, and WG131 transmission series. This OEM genuine part sits within the differential assembly, where it meshes with the ring gear to redirect engine torque from the driveshaft to the axle shafts at a precise right angle. As a hardened steel bevel gear, it ensures smooth, low-noise operation under heavy loads. The SKU 5838.300.721 is manufactured to ZF’s exacting tolerances, guaranteeing a direct replacement that restores factory-grade performance and durability in commercial vehicle drivelines.
Symptoms of Failure
When the ZF 5838.300.721 axle bevel gear wears out, operators often notice distinct failure indicators. Whining or howling noise from the axle housing during acceleration or deceleration is a primary symptom, caused by improper tooth contact. Vibration through the chassis or floorboard at highway speeds indicates uneven gear wear or pitting on the bevel gear surface. Metal debris or glitter in the differential oil during routine fluid changes signals advanced gear degradation. Finally, intermittent driveline clunking when shifting between drive and reverse suggests excessive backlash between the bevel gear and its mating ring gear.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 5838.300.721 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Weight | 2.85 kg (6.28 lbs) |
| Outside Diameter | 168 mm |
| Number of Teeth | 12 (spiral bevel) |
| OEM Reference | ZF 5838.300.721 |
| Heat Treatment | Carburized and quenched to HRC 58-62 |
Compatibility
This axle bevel gear is specifically designed for ZF’s WG-series transmissions. It is a direct fit for the WG100, WG130, and WG131 models. While primarily used in these three series, the 5838.300.721 may also be compatible with certain variants of the WG180 and WG200 transmissions that share the same differential housing geometry. Always verify your transmission model and differential case code before installation. This gear works in conjunction with the 5838109012: DIFFERENTIAL and the 2093209023: DIFFERENTIAL to complete the final drive assembly.
For a full rebuild, the bevel gear must be paired with the 5838300626: DIFFERENTIAL HOUSING and supported by the 0750117075: TAPER ROLLER BEARING to maintain proper preload and gear mesh alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 5838109012 | DIFFERENTIAL | Distributes torque between left and right axle shafts |
| 0750117075 | TAPER ROLLER BEARING | Supports bevel gear shaft radial and axial loads |
| 2093209023 | DIFFERENTIAL | Alternate differential assembly for WG130 series |
| 5838300626 | DIFFERENTIAL HOUSING | Encloses differential gears and bevel gear set |
| 0631329088 | SPRING PIN | Secures bevel gear to differential carrier shaft |
| 5838300811 | THRUST WASHER | Controls axial clearance in differential assembly |
| 5838300633 | AXLE | Transmits rotational force from differential to wheels |
| 5838300753 | THRUST WASHER | Reduces friction between side gears and housing |
| 5838300818 | THRUST WASHER | Thicker variant for backlash adjustment |
| 5838300170 | OUTER CLUTCH DISK | Part of limited-slip differential lockup mechanism |
Frequently Asked Questions
Q: Can I install the 5838.300.721 bevel gear without replacing the mating ring gear?
A: ZF recommends always replacing the bevel gear and ring gear as a matched set. Installing a new bevel gear against a worn ring gear will cause premature noise, accelerated wear, and potential tooth fracture due to mismatched contact patterns.
Q: What is the typical service life of this axle bevel gear in a WG130 transmission?
A: Under normal operating conditions with proper lubrication and no contamination, the 5838.300.721 can last 400,000 to 600,000 kilometers. Frequent heavy towing or off-road use may reduce this interval by 30-40%.
Q: How do I confirm correct backlash when installing this part?
A: After mounting the bevel gear in the 5838300626: DIFFERENTIAL HOUSING, use a dial indicator to measure backlash between 0.15 mm and 0.25 mm. Adjust using the 5838300811: THRUST WASHER or 5838300818: THRUST WASHER as needed.
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Phone: +86 158 2286 3467 |
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ZF 5838.300.721 AXLE BEVEL GEAR – Gear RFQ Support
PartsZF helps B2B buyers source ZF 5838.300.721 AXLE BEVEL GEAR with fast RFQ support, expert part-number lookup, documentation review, and export coordination. This gear 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 5838.300.721 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: DIFFERENTIAL
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 | 5838.300.721 |
|---|---|
| Normalized SKU | 5838300721 |
| Part name | AXLE BEVEL GEAR |
| Product category | gear |
| Cross-reference support | Available for RFQ review |
| Weight | 3.91 |
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.
Related Parts
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- ZF 4143.316.088 PINION
- ZF 4657.302.007 INPUT GEAR
- ZF 4657.354.044 OUTPUT GEAR
- ZF 4644.306.326 GEAR SHIFT HOUSING
