2003-2011 Ford Ranger and 2003-2010 Mazda B-2300 with the 2.3L 4 cylinder interference designed engines and 4R44/5R55 series transmission may incur engine damage after transmission R&R.
To remove the torque converter to flywheel attaching nuts, the starter needs to be removed to provide a small access window to the nuts (figure 1). It then becomes necessary to turn the crank by hand to rotate the converter to remove all 4 nuts. The cause may be that during crankshaft rotation the bolt is loosened causing the un-keyed parts being held together by diamond washers (sprocket and pulley etc.) become misaligned. When the bolt is tightened and it comes time to start the engine, the valves and pistons collide causing major damage to the engine. The same damage will occur if the socket and ratchet was accidently left on the bolt when the vehicle is started. The damage will require extensive engine repair.
If the crankshaft bolt becomes loose during rotation, whether by turning it in the wrong direction or a compression stoke kicked it loose, it will be imperative to align all the parts with a special tool. It will be necessary to consult with a factory manual for tools and procedures to avoid unnecessary and expensive engine damage.