I got thirteen mitsu fuso diesel trucks, and i ve discovered that it takes my drivers alot of energy to turn the steering wheel. What could be wrong with the steering wheel? I ve checked if the trucks have power steering pumps, but they dont ve. Its a manual steering wheel kinna. A friend of mine said i should change the tierod ends and balljoints. Can those be the problem? Meanwhile, the trucks are 04 and 08 model years. Pls guys help me.