Now this probably doesn't apply but in my OMC Cobra shop manual they list a procedure for balancing the actuator valve if it has been changed in the power steering assembly. However, the unit used in the earlier Cobras (86-89) is the same as the old style Merc Alpha actuator and the unit used in later OMCs and Volvos is different, I'm not sure if they have the same set up. On these older units you remove a cap at the end of the control valve after removing the steering cable. With the engine running, you adjust the nut to achieve a balanced condition where the power cylinder rod can be moved in and out manually with the engine idling. It says the only time this needs to be done is when a new actuator valve is installed.