Mercedes Workshop Manual Om646 Engine |link|

A "solid feature" of a Mercedes Workshop Manual OM646 Engine structured assembly-based layout

like a torque specification or a timing chain replacement guide for this engine? Mercedes Workshop Manual Om646 Engine

single, duplex roller chain

The OM646 uses a driving both camshafts from the crankshaft. A "solid feature" of a Mercedes Workshop Manual

• Locking the crankshaft at TDC (Top Dead Center) using a specific pin (part # 601 589 00 63 00).
• Using a chain riveting tool—not a hammer. The manual specifies the exact pressure (kN) for closing the master link.
• Critical warning: Never rotate the engine backward. The manual warns of timing deviation and fuel injection pump damage.