Core Function:
As the central drive component of Mercedes' timing system, it precisely transmits crankshaft power to the camshaft to ensure:
Perfect synchronization between valve timing and piston movement
Optimal air-fuel ratio and combustion efficiency
Coordination with fuel injection and ignition timing systems
Critical Applications:
Mandatory replacement during engine overhaul
Required when timing chain elongation exceeds 3%
Essential repair item for P0016/P0017 fault codes
| Feature | Technical Advantage |
|---|---|
| Dual-phase alloy steel | Tough core (impact-resistant) + 60HRC surface hardness (300% wear resistance increase) |
| Asymmetric tooth profile | 7dB noise reduction vs conventional gears |
| Laser-etched timing marks | 90% improvement in installation error prevention |
| Nano-composite coating | 0.08 friction coefficient (40% lower than standard gears) |
| Hollow lightweight design | 18% reduced rotational inertia for better engine response |
Power Transmission Path:
Crankshaft gear → Timing chain → This gear → Camshaft → Valve train
Synchronization Precision:
≤0.5° crankshaft angle deviation (equivalent to <0.1mm gear backlash)
Dynamic compensation: Hydraulic tensioner maintains constant chain tension
| Engine Code | Compatible Models | Model Years | Special Notes |
|---|---|---|---|
| M274 DE20 LA | C300(W205)/GLC260(X253) | 2014-2018 | Must upgrade guide rails simultaneously |
| M276 DE35 | E400(W212)/ML350(W166) | 2010-2017 | Not for AMG-tuned versions |
| OM642 DE30 LA | GL350(CDI)/S350D(W222) | 2011-2019 | Requires sulfur-resistant grease |
Critical Steps:
Position Locking:
Use MB SST 000-589-00-30-00 to secure crankshaft at TDC
Camshaft alignment holes must match perfectly (<0.2mm tolerance)
Torque Procedure:
Stage 1: Pre-tighten 50Nm → Stage 2: Final 80Nm → Stage 3: Additional 90° rotation Prohibited Actions:
Never use impact wrenches (causes micro-deformation)
Stretch bolts are single-use only (MB mandatory standard)
| Symptom | Root Cause | Solution |
|---|---|---|
| Cold start "clicking" | PVD coating wear | Replace full timing set (chain+tensioner) |
| P0017 fault code | Gear keyway misalignment | Inspect crankshaft woodruff key |
| Abnormal oil consumption | Sealing surface deformation | Check cylinder head flatness (<0.05mm) |
| High-RPM power loss | Heat treatment defects | Verify part authenticity (counterfeit risk) |




