Overview
The ZF 4661.374.003 INNER DISK CARRIER is a precision-machined component designed for the clutch pack assembly within WG90 and WG94 series transmissions. This OEM genuine part functions as the rotating hub that houses and aligns the inner friction disks, ensuring proper torque transfer during gear engagement. Located directly within the main transmission housing, the carrier interfaces with the piston assembly to apply clamping force to the disk stack. The SKU 4661.374.003 is manufactured to ZF’s exacting tolerances, guaranteeing concentricity and surface finish for reliable clutch operation under heavy-duty industrial loads.
Symptoms of Failure
- Delayed or harsh gear engagement: A worn inner disk carrier can cause uneven pressure distribution across the clutch pack, leading to noticeable hesitation or jerking when shifting between forward and reverse gears.
- Transmission oil contamination: Cracks or scoring on the carrier’s spline surfaces generate metallic debris that circulates through the hydraulic system, often visible as glitter in the oil pan during routine checks.
- Progressive power loss under load: As the carrier’s spline teeth wear, the friction disks slip intermittently, causing the transmission to lose torque capacity during uphill climbs or heavy hauling operations.
- Audible grinding from the clutch housing area: Excessive radial play between the carrier and the TRANSMISSION HOUSING produces a low-frequency metallic noise that intensifies with engine RPM.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4661.374.003 |
| Material | Case-hardened alloy steel (16MnCr5 equivalent) |
| Outer Diameter | 185 mm (estimated) |
| Inner Spline Diameter | 135 mm (estimated) |
| Overall Height | 48 mm (estimated) |
| Weight | 2.4 kg (estimated) |
| OEM Reference | ZF 4661.374.003 |
| Surface Finish | Ground spline flanks, phosphate coated |
Compatibility
This inner disk carrier is engineered for ZF WG90 and WG94 series transmissions, which are commonly installed in off-highway trucks, wheel loaders, and agricultural tractors. Based on the part’s design and spline configuration, it is also compatible with the WG180 and WG200 models that share the same clutch pack architecture. The carrier works in conjunction with the HOUSING and the TUBE to form the complete clutch assembly. A CYLINDRICAL PIN secures the carrier to the hub shaft, preventing rotational slippage during high-torque events.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101001 | TRANSMISSION HOUSING | Encloses the gear train and supports bearing bores |
| 4661301007 | HOUSING | Contains the clutch pack and valve body |
| 4661301093 | TUBE | Routes hydraulic fluid to the clutch piston |
| 0631306174 | CYLINDRICAL PIN | Aligns and locks the carrier to the shaft |
| 0769123894 | TYPE PLATE | Identifies transmission model and serial number |
| 0750100022 | SCREW PLUG | Seals hydraulic test ports |
| 0636302602 | SCREW PLUG | Closes oil drain passages |
| 0634100633 | O-RING | Prevents fluid leaks between mating surfaces |
| 4661301029 | NOZZLE | Directs lubrication to the clutch disks |
| 4661301027 | NOZZLE | Sprays cooling oil onto the carrier splines |
