Overview
The ZF 4644.102.100 INPUT is a critical torque-transfer component engineered specifically for the WG180 and WG200 series transmissions. This OEM genuine part serves as the primary connection point between the engine output and the transmission’s internal gear set, ensuring precise rotational alignment and load distribution. The SKU 4644.102.100 is designed to withstand high cyclic stresses while maintaining minimal backlash, directly influencing shift quality and driveline efficiency. Located at the front of the transmission housing, this input shaft interfaces directly with the 4644105413 DISCONNECTION assembly and the 4642303093 OUTPUT FLANGE to complete the power flow path.
Symptoms of Failure
- Audible gear whine or grinding during acceleration: Worn splines on the 4644.102.100 INPUT cause uneven load distribution, producing a high-pitched noise that intensifies under load.
- Intermittent gear slipping in higher ranges: Degraded input shaft bearing surfaces lead to axial play, resulting in momentary loss of torque transfer, especially in WG180 and WG200 transmissions.
- Transmission fluid seepage near the bell housing: A worn input shaft seal surface allows ATF to bypass, often leaving visible drips after extended operation.
- Vibration through the shift lever or chassis: Misalignment from a fatigued input shaft causes harmonic vibrations that worsen at specific RPM ranges.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.102.100 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Overall Length | 312 mm (estimated) |
| Spline Major Diameter | 42 mm (estimated) |
| Weight | 4.8 kg (estimated) |
| OEM Reference | ZF 4644.102.100 |
| Surface Treatment | Black oxide + phosphate coating |
Compatibility
This genuine ZF input shaft is factory-specified for the WG 180 Series and WG 200 Series transmissions. It is also compatible with select ZF off-highway and industrial drivetrains that share the same spline geometry and bearing journal dimensions. When replacing the 4644.102.100, always inspect the 0636021010 HEXAGON SCREW for thread wear and verify the 4644101222 TRANSMISSION HOUSING for cracks or distortion. For complete rebuilds, pair this input with the 4644301226 TRANSMISSION HOUSING and 4644301298 COVER PLATE to ensure proper sealing and alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105413 | DISCONNECTION | Engages/disengages input shaft from engine |
| 4642303093 | OUTPUT FLANGE | Transfers torque to driveshaft |
| 0636021010 | HEXAGON SCREW | Secures input shaft bearing retainer |
| 4644101222 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301226 | TRANSMISSION HOUSING | Alternate housing variant for WG200 |
| 0730365067 | TYPE PLATE | Identification label for transmission model |
| 0631311009 | GROOVED STUD | Alignment dowel for housing assembly |
| 4644301298 | COVER PLATE | Seals input shaft access port |
| 0634306525 | O-RING | Hydraulic seal for input shaft bore |
| 0636305026 | SCREW PLUG | Closes oil gallery in housing |
