How Much Should a Ball Joint Move By Hand?

Maintenance/Repairs
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1

I’m able to move my sway bar links by hand, while they are attached to my car properly. Not movement perpendicular to the shaft of the ball joints (black line below)
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I’m able to grab on the bar between the ball joints and rotate it (red line) with ease using my hand (maybe 30 degrees or so in either direction (estimate)).

I understand that that movement perpendicular to the shaft is indication of a bad ball joint? However isn’t some movement indicated by the red line desired? I’m not sure how much movement is acceptable in this direction, and if I should be able to rotate it freely by hands?

I see online, when movement greater than specified by the manufacturer is observed, then replace the ball joint. I can’t find any specifications on how much movement is acceptable though. Even when I look at aftermarket replacement parts from online retailers.

Thanks for any help in clarifying how much ball joint movement is acceptable, and if I should be able to rotate by hand.

2

Movent in that direction is completely fine. The joint should be free to move rotationally in all axis to some degree. That’s why it is called a ball joint. Any axial loosness is reason for replacement.

You’ll know when replacement is due because you will hear a tappinig noise when one wheel goes over a bump.

2 Likes
3

Thanks for the help. That’s what I thought. Just wanted to make sure.

4

Shouldn’t be able to move the shaft in the direction of the black lines, or in the direction of the shaft’s axis. As mentioned above, it’s ok to be able to rotate the shaft somewhat by hand.