Overview
The ZF 4108.303.281 PLANET CARRIER is a critical rotating assembly within the planetary gear set of heavy-duty ZF transmissions. This OEM genuine part serves as the structural hub that holds the planetary gears in precise alignment, transmitting torque from the sun gear to the ring gear while managing immense radial and axial loads. Located inside the main transmission housing, the planet carrier directly influences gear ratio engagement and overall driveline efficiency. The SKU 4108.303.281 is engineered to OEM tolerances, ensuring exact fitment and load distribution across the gear train. When this carrier fails, it compromises the entire planetary stage, often requiring replacement of adjacent components such as the 4108101115: HOUSING and the 4108201277: HOUSING to restore full transmission integrity.
Symptoms of Failure
- Erratic gear engagement or slipping under load: Worn planet carrier bores or cracked carrier arms allow planetary gears to misalign, causing intermittent power loss during acceleration or climbing.
- Metallic grinding noise from the transmission sump: As the carrier bearing surfaces degrade, metal particles contaminate the oil, producing a distinct grinding sound that intensifies with RPM.
- Oil leaks near the transmission output flange: A fractured carrier can distort the 4108301304: BEARING COVER, breaking the seal and allowing ATF to escape past the shaft.
- Vibration in the driveline at specific gear ranges: Uneven wear on the carrier’s pinion pockets creates rotational imbalance, felt as low-frequency vibration through the chassis.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4108.303.281 |
| Material | Forged alloy steel (case-hardened) |
| Weight | 8.7 kg (19.2 lbs) |
| Outer Diameter | 185 mm |
| Overall Height | 95 mm |
| Pinion Bore Count | 4 (symmetrical) |
| OEM Reference | ZF 4108.303.281 |
| Surface Treatment | Black oxide + phosphate coating |
Compatibility
This planet carrier is designed for ZF’s WG series powershift transmissions commonly used in construction machinery. It is a direct replacement for the following transmission models: WG180, WG200, and WG210. These transmissions are found in wheel loaders, graders, and telescopic handlers from manufacturers such as Volvo, Case, and JCB. Always verify the transmission serial number before installation, as minor revisions exist between early and late production units.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4108101115 | HOUSING | Encloses the planetary gear set and supports the carrier shaft |
| 4108201277 | HOUSING | Rear housing section that aligns the output shaft |
| 0501313402 | DRAIN VALVE | Controls fluid evacuation during service intervals |
| 4108301304 | BEARING COVER | Seals the carrier bearing and prevents contamination |
| 4108306173 | GASKET | Provides leak-proof seal between housing interfaces |
| 0750110040 | SHAFT SEAL | Prevents oil migration along the rotating shaft |
| 4108111051 | POWER TAKE-OFF | Transfers engine power to auxiliary hydraulic pumps |
| 0730106757 | WASHER | Thrust washer for carrier axial clearance |
| 0730106758 | WASHER | Intermediate thrust washer for gear spacing |
| 0730106759 | WASHER | Outer thrust washer for load distribution |
