Ball Joint Nut

Hello all. Just did the entire front end swap/install with new equipment on my grand marquis. My question:

I installed the lower control arm and torqued the nut at the steering knuckle to specs listed in the manual I can’t remember the foot pounds but in any case, when I turn the steering wheel left and right the nut will spin as well even though it’s tight. Is this cause the ball joint is new and the grease hasn’t had time to work into the ball joint yet? Kinda worries me. This nut shouldn’t turn I thought!

I believe that you have installed an incorrect part. The ball joint threaded stud should be tapered to fit the knuckle and it sounds as though you have been sold a ball joint with a smaller stud. Was the same size nut on the old ball joint and the new one?

Thanks for the reply rod. The old part and new part are the same size as far as the nut goes. The stud on the old part and new part were both slightly loose in the steering knuckle. Just don’t want it to loosen itself with each turn of the wheel. I can throw some loctite on it but I’m trying to avoid that

@Josh; post your model year Marquis. I checked and some Fords now use a seperate bevelled seat to mate the ball joint stud to the knuckle. Compare what you removed with what you installed. Of course that’s always good practice.

1996 model year. When removed it was just the stud. And the nut on top mounting it to the knuckle. I didn’t care about the boot so I used a pickle fork to remove it and it was a bear to separate. 20 years of rust. The new part has a tapered stud and the same size nut. I’m stumped on this one

The threads on the stud might just end a little too soon, manufacturing tolerances being what they are (poor on some aftermarket parts). The nut is supposed to draw the stud into the knuckle so it seats hard against the taper. It should NOT turn with steering.

Remove the ball joint’s nut and check for shiny marks. Are they on the bottom of the nut? (likely, no) they may show on the threads themselves. That’s not right. The nut has to draw against the knuckle so add an SAE washer, not the soft ones in the general hardware bin and try again. When it seats properly, there is no rotation of the nut and stud relative to the knuckle.

Have you attempted to re-tighten the nut? You may find that the nut and stud will now turn and it will be difficult to remove the nut. I can’t imagine anything other than an incorrect ball joint causing such a problem. The Moog part has a tapered stud that should wedge tightly into the knuckle.

Thanks for the great replies. I will try to remove the nut and check what you mentioned mustang. Ill report back. I’ll also grab an sae washer at the zone. I will then re torque it and see if it still turns when the wheel is turned. If so then I don’t know what to do. If I can’t loosen the nut rod then I am stumped again. Of course there’s nowhere to hold the stud while turning the nut (such as an upper shock mount bolt)

Remove the cotter pin and tighten the nut until the tapered stud gets pulled into the steering knuckle tightly. Then reinstall the cotter pin.


The stud on the old part and new part were both slightly loose in the steering knuckle.

I’m a little worried that you’ve worn the hole in the steering knuckle such that it won’t tighten correctly.

I had a loose stud once and it wore the hole too big. It doesn’t take much to ruin the socket. Mine finally stayed tight but had to work at it.

First time the LCA has ever been replaced, I hope theres not a hole worn bigger in the steering knuckle. That would be quite a bit concerning to me. The hole that receives the stud was pretty much brand new on the inside. No rust, or corrosion.

I am going to check the torque today on the nut and see if its still at the 90 or whatever the foot pounds was (dont have the info with me right now from the haynes manual). If its still holding the torque AND still turning in the hole then it makes me want to throw a new ball joint in there. Safety first!