How do u know when it's bad? Went to get it aligned and was told it was bad. The ball stud was moving back and forth. Looked on the internet and it said it was supposed to move that way. Did some searches on here about steering and i think it's power assisted , according to one thread i read. thanks oh it's a 69 coupe

 

can anyone help?

 

ive got a prob with my ps control valve on my 70 rag ive been thinking about changing over to manual steering mustangs unlimited have a conversion adapter at $159 but have not found out if its any good do you have any ideas

 

There will always be a lot of play in the ball stud IF the engine is not running and the hydraulics are not working. With the engine running, the play should pretty much disappear as the linkage should follow the ball stud and not allow any play.
If there is noticable play with the hydraulics working, the control valve & ball stud assembly should be rebuilt.
More information available here: http://www.stangerssite.com/steering.html