Upper Control Arm
bushings and ball joints
Authored by Wes Vann, Created July 4, 2001
Caution!!! There is a certain amount of danger when playing around with the front springs. They are under a lot of pressure and if you do something wrong they could come out and bite you. If something seems "wrong" with what you are doing, that's your brain trying to save your body from harm. Listen to it!
Take it slow, take your time (don't drink a ton of beers!), and everything will be ok.
What I'm going to show is how I replaced the bushings and ball joints on a 79 Pontiac that I own. It's all the same on an early Chevelle or Camaro, so I don't feel guilty putting it here.
All of the photos will be "clickable" to a larger version, should you want to see it. I'm not the best with taking photos and tried to change the brightness and contrast so they are easy to see. Don't expect magazine quality!!
There were no big dollar tools required! You will need a 3/8" allen socket to remove the disk brake caliper. You should also go out and buy a piece of 2" by 2" angle iron that is about 18" long. (get the angle iron before taking anything apart!)
Removing the arm;
Put the car up on good jack stands and pull off the wheel. I normally shove the wheel under the frame just as a precaution.
This photo is actually what it looks like when I was finished. (I didn't take a good photo before starting)
Disconnect the sway bar from both lower control arms. It's just a big long bolt on each end. You may want to think about replacing the bushings here also. The reason that you want to do this is that you are going to have to swing the lower control arm downward latter, and the sway bar will prevent this. Disconnecting both ends makes it easier to move the sway bar if it gets in the way.
Now remove the shock absorber. There are two bolts that come from below the lower control arm and go into nut "clip plates". If the clip plates get broken, plan on buying new ones. The top of the shock is removed by getting to the nut within the engine compartment. The "shaft" of the shock should have a pair of flat edges that you can put a wrench on to prevent the shaft from rotating.
From within the engine compartment, remove the two nuts on the end of the control arms cross-shaft. (if you don't know what the cross-shaft is, there is a photo farther down on the page) The reason that you are removing them now is that with the shaft still attached to the frame, it will not just rotate freely.
Remove the disk brake caliper, but before you do, plan on how you are going to "hang" it!
My fingers are pointing to the two "pins" that the caliper "floats" on. They are allen head pins and you will need a 3/8" allen head socket to remove them. (that's the socket in the other photo) Plan on being able to use a large breaker bar on this as they tend to get tight.
I normally just use a piece of welding rod to hang the caliper.
Now is a good time to sit back and think about things! The front spring is pushing down on the lower control arm and if you bang on it, you can tell that it's still under a lot of compression. The lower arm is pulling down on the spindle and it's pulling down on the upper arm (the very one we plan on removing!). The only reason that everything doesn't go farther downward is that the upper arm is resting on it's rubber "stop".
Put a floor jack under the lower control arm and pump it up until it just touches the arm.
What you want to do now is remove the cotter pin on the upper ball joint's nut. Then carefully unscrew the nut until it's as shown in the photo below. Don't remove it!!!!
As I talked about just a little while ago, the spring is trying to pull this connection apart. Some times, all it takes is a few taps with a hammer on the side of the spindle to snap it free.
"Snap" isn't really a good word for it. When it lets go, you will be amazed with the power released. (be sure your fingers are not between the nut and spindle at any time!)
The "tapping" with a hammer didn't do it for me and I had to use my "pickling fork". This is an item that you wedge between the spindle and the upper arm. Then beat on it with a hammer to drive it in.
This popped the thing loose. (keep in mind that the nut is still in place)
Now you should pump up the floor jack so that it moves the spindle upward and the upper arm comes off it's bump stop. Make sure that your jack will hold a setting and not lower over time.
From within the engine compartment, you should remove the two nuts that hold the cross-shaft to the frame. Something to keep in mind is that the bolts shouldn't be removed! On the early G.M.'s they had a spline that kept them from rotating. If you mess up the splines, tightening it back down becomes a major pain. Another thing that you have to keep track of is the shims that are on both the front and rear studs. These have to go back to the same locations or you will throw off the alignment!
At this point, you can remove the nut from that upper ball joint. You should be able to remove the arm at this point. (I was working on the drivers side and was able to get it out without moving the steering shaft)
Before going anywhere, make sure that nobody will be messing with that floor jack!
Taking apart the arms;
The control arm is on the ground and what we are going to do now is remove the old (original) ball joint.
When the factory assembles the upper control arms, they use four rivets to hold the ball joint in place. This photo is a view from the top and if you look closely, you can make out a couple of the rivet heads.
You will have to drill out the rivets or grind off the heads. I have a 4" grinder and decided to go that way.
Here the rivet heads have been ground off and it still didn't want to come apart. What I found out is that the rivets had mushroomed out to the depth of the sheet metal cover plate (that upper plate that has the grease fitting). I had to grind down farther than I first thought I would have to.
To remove the bushings, I used a piece of angle iron that I had around the garage. No magical numbers here, but I'd recommend that you go out and get a piece of 2" by 2", heavy angle iron that is about 18" long. Alternate sides of the bushing as you are trying to hammer it out.
Here is a photo of the stripped down and cleaned a-arm.
This is what you will get when you buy a replacement ball joint. All the bolts and everything should be included!! You don't have to drill any new holes. The bolts go through the holes where the rivets were.
Now before you go bolting the ball joint on the arm, there are two things to check first. If you have to drill any holes in the arm for the bolts, you have the wrong ball joint!
Take the ball joint and slide it into position in the spindle. The taper of the ball joint shaft should match the taper of the spindle exactly! If it doesn't, it's the wrong ball joint! While it's still there, make sure that there isn't any problem with getting the nut on. The shaft length should be the same length of the original ball joint.
Follow the instructions that came with the ball joint and attach it to the upper arm. I'd recommend that you use loc-tite on the threads.
At the top of this photo is the original cross-shaft.
Below it is what is called an "off-set cross-shaft".
Also shown is (from left to right) a "serrated" washer, rubber bushing, large diameter washer, and "deformed thread" nut.
Now we go off on some little tangents;
This whole project started due to a "clunk" in the front-end. It was due to the arm being able to move forward and back along the cross-shaft. The reason was that the metal sleeve on the bushings had worn loose. This plus the fact that one of the serrated washers had worn away.
Well, it was possible to get new bushings and the cross-shaft wasn't damaged, but you can't buy the serrated washers!!!!!! The only way you could get them was to buy a complete cross-shaft "kit".
Although I didn't need an "offset" cross-shaft, they don't make a standard shaft anymore (for this installation).
I ended up measuring what the offset is and had to add shims when I put the assembly back into the car.
Another tangent is to explain what a "deformed thread" nut is. It's a nut with slightly messed up threads that will not vibrate loose. (I wonder if there is a mil-spec version of deformed threads)
Ok, we're back from the tangents.
To install the rubber bushings, I used a large socket and hammer. Nothing too colorful just make sure that you don't cock the bushings as you are trying to drive them in.
Start with installing one of the rubber bushings, without worrying about the cross-shaft.
When you install the other bushing, you have to make sure that you have installed the cross-shaft and all the washers. If you don't do it correct, you will have to trash one of the bushings in order to take it apart. Read the instructions that come with the kit!
Install the deformed thread nuts and washers, but don't worry about tightening them at this time.
These two photos show the arms fully assembled.
Notice that the photo on the right shows that the grease fitting has been installed. It's a good idea to do this early to prevent any dirt from entering.
Putting it back together;
Put the arm back into position and slide the cross-shaft on the mounting bolts (studs). Thread the nuts onto the studs, but don't worry about tightening them yet.
Slide the ball joint shaft onto the spindle and install the nut. Tighten it down "snug".
Reinstall the shims that you removed from between the cross-shaft and the frame. Tighten the nuts. Due to my having to use an "off-set" cross-shaft, I had to add additional shims to cancel out the offset.
Tighten the ball joint nut and install the cotter pin!
Reinstall the shock absorbers. Sometimes it helps to jack up the lower control arm so that the "reach" of the shock is ok.
Remove the floor jack.
Install the disk brake caliper.
Reinstall the sway bar "links". (new ones don't cost that much)
Grease the ball joint!!!!
Put the wheel back on and lower the car.
From within the engine compartment, you should now tighten the two cross-shaft nuts. It would be easy to walk away once the car is back on the ground, but you would earn instant "jerk" status if you leave these loose! You want to do this when the car is on it's wheels so that you don't "preload" the bushings with a twist.
If you haven't had the alignment done in quite some time, it may be a good idea to have it checked out.
Wes.