Hear is the list of Tecknics gears available,these gears are very durable with virtually no free play,bearing blocks and shafts to U joints are also available at super cheap prices,the endless applications of Tecknics to submarines systems is amazing!
Also if your hull does not allow for easy access to the forward section after construction,the mechanical method might not work out well as it is difficult to install in that area and when removing the casing the shafts and rods must re aligned exactly the same.
That is why I go with hydraulics as only the electrical to the "in the wet " gear pump is disconnected,the rest is already installed and is not disturbed.A mixture of hydraulics and mechanical gears is what is made to do the job smoothly ,realistically and very affordable.

http://www.bricklink.com/catalogList...;catString=136