Chain tensioner removal and installation procedure for engine 639.939 in Smart Fortwo 454 with sealing ring and torque specification.

Chain tensioner assembly diagram with numbered callouts and service procedure table for Smart Fortwo 454.

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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.