Should mazda 6 remove the camshaft and the timing front cover?

1. Remove the valve cover, remove the crankshaft pulley, remove the timing chain cover, turn the crankshaft, turn the crankshaft to 1 cylinder top dead center, and tighten the crankshaft fixing screws to fix the crankshaft; 2. Turn the intake and exhaust camshafts with grooves at the rear end, so that the grooves of the two camshafts are balanced and aligned, and clamp the special tools; 3. Remove the old chain and install a new one. Crankshaft pulley also has no sliding key. During installation, there is a round hole on the pulley, which is aligned with the groove on the chain shell.

It is located at the top dead center of the crankshaft. There is a six-kilometer-long screw hole on the outer edge of the crankshaft pulley, which must be aligned with the screw hole of the timing front cover.