Overview
The ZF 127002400643 BEVEL SCREW is a precision-engineered fastener designed for the differential assembly within ZF WG100, WG130, and WG131 transmissions. This OEM genuine part secures the bevel gear set to the differential housing, ensuring precise rotational alignment under high torque loads. The SKU 127002400643 is manufactured to ZF’s exacting tolerances, preventing axial play that can lead to premature wear of the CROWN WHEEL and DIFFERENTIAL assembly. As a critical component in the final drive system, this bevel screw maintains the integrity of the gear mesh, directly influencing power transfer efficiency and drivetrain longevity.
Symptoms of Failure
- Whining or howling noise from the differential: A worn or loose bevel screw allows the DIFFERENTIAL HOUSING to shift, causing irregular gear contact patterns that produce audible noise during acceleration or deceleration.
- Vibration under load: When the 127002400643 loses clamping force, the bevel gear set develops backlash, transmitting vibration through the transmission housing and into the vehicle chassis.
- Metallic debris in transmission fluid: A failing bevel screw permits micro-movement between the gear and housing, generating fine metal particles that contaminate the lubricant and accelerate wear on the DIFFERENTIAL components.
- Intermittent gear slippage or clunking: Severe loosening of this fastener can cause the bevel gear to momentarily disengage from the crown wheel, producing a distinct clunk and momentary loss of drive torque.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 127002400643 |
| Type | Bevel Screw (Shoulder Bolt) |
| Thread Size | M12 x 1.5 |
| Overall Length | 45 mm |
| Shoulder Diameter | 16 mm |
| Material | Case-hardened alloy steel (20MnCr5) |
| Surface Treatment | Zinc-nickel plating, 8 µm |
| Weight | 0.048 kg |
| OEM Reference | ZF 127002400643 |
| Torque Specification | 85 Nm + 90° angle |
Compatibility
This bevel screw is specifically engineered for ZF WG-series transmissions, including the WG100, WG130, and WG131 models. It is also compatible with the WG180 and WG200 series when used in the differential bevel gear mounting position. The 127002400643 replaces earlier part numbers 127002400640 and 127002400641. For proper installation, always pair this screw with a new THRUST WASHER and BALL BEARING to ensure correct preload and axial clearance.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 2098109042 | DIFFERENTIAL | Distributes torque to axle shafts |
| 2098309011 | CROWN WHEEL | Drives differential carrier |
| 2099209001 | DIFFERENTIAL | Complete differential assembly |
| 2098309010 | DIFFERENTIAL HOUSING | Encloses gear set |
| 2098309009 | DIFFERENTIAL HOUSING | Alternate housing variant |
| 2098309031 | AXLE BEVEL GEAR | Transfers power to axle |
| 2098309030 | AXLE BEVEL GEAR | Left-side bevel gear |
| 2098309032 | DIFFERENTIAL BEVEL GEAR | Spider gear set |
| 12883200682 | THRUST WASHER | Controls axial clearance |
| 0635332059 | BALL BEARING | Supports rotating assembly |
