Removing and installing tensioning rail on 454.0 engine 639.939 with numbered callout diagram and procedure table.

Engine tensioning rail removal diagram with bearing pin and belt pulley callouts for Smart 454.0

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See all Powertrain figures for the Fortwo / Forfour (453), or browse the full figure library. Part numbers and callouts are community-sourced and cross-referenced against the manuals — confirm with your VIN before ordering.