90K miles on my 2006 XK. I am trying to replace the front suspension upper control arms because the ball joint dust covers were falling apart, and started on the RH (passenger) side. I am at the point in the service manual instructions where it is necessary to remove the 19 mm nut that attaches the ball joint to the RH wheel knuckle. I applied penetrating oil spray to the nut and the threaded shaft.

The threaded shaft from the ball joint has a concentric hole which was intended to hold a hex key to keep the shaft from spinning while loosening the nut. Unfortunately, that hole became rounded. So I removed the remnants of the rubber cover over the ball joint, and tried to use pliers to hold the portion of the shaft previously covered by the dust cover, while turning the 19 mm nut. That is not working very well.

Any suggestions from the group?

Also - what is the point of releasing the lower suspension arm from the wheel knuckle? How does that help to remove the strut assembly?
Thanks!

 

Try using one of those locking vise grip wrenches to hold it.

You probably have to release the lower arm to knuckle so that its easier to remove the strut. Just make sure you have a jack stand or something supporting the knuckle after you release the arm and strut.

 

not terribly familiar with this on our cars, but on a lot of cars in general, this is just another ball joint or something just like it, and you aren't going to ever get the nut loose if you take the strut and lower control arm off the car together. most directions will say to do it just to have it done and dusted then and there when the weight of the car on the suspension makes it easy.

you can try to grind a flat on the shaft of the ball joint, which will give better purchase for a vise grip, but you'll obviously have a hard time with that in a tight spot. and if you're going to do something destructive at all, well, you might as well just cut a slot into either side of the nut and then hammer+punch it off the threads.

 

Sawzall

 

When I’ve run into this in the past (on other vehicles), I use a floor jack to push upward on the assembly, forcing the ball joint cone further into the arm. It’s usually enough friction to allow the nut to come off, but not always. It’s easy to try, at least.

 

Thanks for the replies!

Here is what I have done so far today:

I used a Dremel tool with metal cutting wheel to cut two vertical slots into two faces of the nut, on the lower edge that has the nylon locking ring. If I cut too deeply into the threads of the shaft, will that cause more problems than help? If the cutting won't jam the threads, should I cut six vertical slots into the six faces of the nut?

I had two vise grips in my toolbox but they were both relatively thick and did not do a good job grabbing the shaft. So I bought another vice grips tool which has a shape more like long nose pliers and is thinner. It does a better job of gripping the shaft but still slips. I tried jacking up the bottom of the suspension to change the load on the nut, that did not help.

I tried using a corded Makita impact wrench. The wrench is sufficiently long so that I had to use a universal joint and an 8" extension to access the nut. That did not help.

I bought a Makita reciprocating saw (a Sawzall version) with extra "thick metal" blades from Home Depot, but have not used that yet. The purpose of that saw could be to cut the shaft just below the ball joint, to free the shaft from the ball joint. However I have not done that yet because I am concerned that I still will not be able to get an adequate grip on the shaft using the vise grips. Worst case, I would have to replace the wheel knuckle.

 

It’s true, you can’t get the strut out without releasing the lower control arm (did that when replacing my struts a couple years ago, and will do it again this year).
Don’t need to worry about the knuckle dropping, it’s still supported by the rest of the suspension. Actually need to use a lever to pry the knuckle lower to give clearance to get the strut out. Use a jack to raise the knuckle to the right height when reinstalling the strut.

 

Since you’ve already cut the nut, why not use a nut splitter/cracker and break the nut off?

 

I did not know that such a tool existed! I think I will try using the Dremel tool more tomorrow to see if that will work. If not, I will get a nut splitter tool. Thanks for that suggestion!

 

i would typically be replacing the entire ball joint, not just the nut -- so i would think you could cut all you want, even into the threads.

as to the number of them, with two good slots in the nut, you can usually pound the thing right off the threads with a hammer and a punch or chisel. just tuck the punch/chisel into the cut and aim to hit it so it spins the nut off, or just splits in half. the extra slots shouldn't be needed.

 

i'm too cheap to buy one

 

I decided to place a nut splitter tool order with Amazon since they could deliver on Sunday - a set of four tools for different nut sizes. I am going to mess around with the Dremel on Saturday and try your idea of hitting the nut with a chisel and small sledgehammer. If that doesn't work then the nut splitter tool will show up the following day.

 

Thanks again for this suggestion! I bought a four-sizes nut splitter kit from Amazon for $38.99 and it arrived at 2 PM today. I immediately tried the second largest nut splitter from the kit and it worked! It opened up the existing cut that I had made in a face, into an inverted V shape split. That was sufficient deformation so that I could remove the nut using a 19 mm socket, while using the vise grip tool to hold the top of the shaft (the area previously covered by the rubber joint cover.)

I was able to install the new RF (passenger side) upper suspension arm without further problems. I removed the top and bottom hardware securing the strut, but did not actually remove the strut. I just moved the strut from side to side in order to remove the bolts holding the upper suspension arm. I also removed the bolt holding the lower suspension arm to the knuckle, however the lower arm remained in contact with the knuckle at all times.

Then I started work on the LF (driver's side) and was more careful when removing the upper suspension arm ball joint nut. I hammered the hex bit socket into the bottom of the joint's threaded shaft so that the hex bit was fully seated and would not slip.

Based on another member's posting, I had bought a long combination 17 mm/19 mm ratcheting box end wrench and that was perfect for removing that ball joint nut as well as the nuts hiding by the coolant reservoir and the engine control unit.

I hope to finish up replacing the LF upper suspension arm by Tuesday this week.

I was nervous about the knuckle pivoting outwards while it was disengaged from the upper suspension arm, as that was putting stress on the flexible brake line leading to the caliper. As you suggested, a hydraulic floor jack was great in raising up the knuckle when it was time to reinstall the strut.

 

Glad to hear you’re making progress!

 

Yes, and I finished up earlier today. Thanks again to all who provided their suggestions and ideas.

 

Hi Patrick
Glad you are sorted but to advise you it's a torx socket not hex that's needed to stabilise the ball joint which is how it ended up being rounded off. I think the size is t30 off the top of my head.
If you have further ball joint boots split, you can just replace the boot with an aftermarket one which are far better than the OEM ones. There is a sticky about the job.
Andy

 

Patrick, did you search for boot covers or just go with new control arm due to miles? I have 2012 with 49k babied miles and same issue with torn control arm boot covers. Would be great if someone knows correct size so can just replace boots as my joints are perfect. A place in UK and one in Bulgaria have many sizes and forum members on older cars ordered/replaced theirs but can't find anywhere on forum for X150's. If anyone knows size please reply, older models used 15mmX30mmX23mm height but not sure if same on XK's. Local dealer said my joints all solid but they can only get full parts not just boots and $4,400!!

 

Hi Mike, I did not look for boot covers and do not know what the correct size would be. The new parts purchased from a Ford dealer are quite inexpensive. Good luck with your search.
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