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 comeout 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 79Pontiac that I own. It's all the same on an early Chevelle or Camaro, so I don'tfeel guilty putting it here.
All of the photos will be "clickable" to a larger version, shouldyou want to see it. I'm not the best with taking photos and tried to change thebrightness 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" allensocket to remove the disk brake caliper. You should also go out and buy a pieceof 2" by 2" angle iron that is about 18" long. (get the angleiron before taking anything apart!)
Removing the arm;
Put the car up on good jack stands and pull off the wheel. I normally shovethe wheel under the frame just as a precaution.
This photo is actually what it looks like when I was finished. (I didn't takea good photo before starting)
Disconnect the sway bar from both lower control arms. It's just a biglong bolt on each end. You may want to think about replacing the bushings herealso. The reason that you want to do this is that you are going to have to swingthe 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 theway.
Now remove the shock absorber. There are two bolts that come from below thelower control arm and go into nut "clip plates". If the clip platesget broken, plan on buying new ones. The top of the shock is removed by gettingto the nut within the engine compartment. The "shaft" of the shockshould have a pair of flat edges that you can put a wrench on to prevent theshaft from rotating.
From within the engine compartment, remove the two nuts on the end of thecontrol arms cross-shaft. (if you don't know what the cross-shaft is, there is aphoto farther down on the page) The reason that you are removing them now isthat 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 goingto "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 onbeing 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 ispushing down on the lower control arm and if you bang on it, you can tell thatit's still under a lot of compression. The lower arm is pulling down on thespindle and it's pulling down on the upper arm (the very one we plan onremoving!). The only reason that everything doesn't go farther downwardis 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 justtouches the arm.
What you want to do now is remove the cotter pin on the upper ball joint'snut. Then carefully unscrew the nut until it's as shown in the photo below. Don'tremove it!!!!
As I talked about just a little while ago, the spring is trying to pull thisconnection apart. Some times, all it takes is a few taps with a hammer on theside of the spindle to snap it free.
"Snap" isn't really a good word for it. When it lets go, you willbe amazed with the power released. (be sure your fingers are not between the nutand 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 spindleand 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 andthe upper arm comes off it's bump stop. Make sure that your jack will hold asetting and not lower over time.
From within the engine compartment, you should remove the two nuts that holdthe cross-shaft to the frame. Something to keep in mind is that the boltsshouldn't be removed! On the early G.M.'s they had a spline that kept them fromrotating. If you mess up the splines, tightening it back down becomes a majorpain. Another thing that you have to keep track of is the shims that are on boththe front and rear studs. These have to go back to the same locations or youwill throw off the alignment!
At this point, you can remove the nut from that upper ball joint. You shouldbe able to remove the arm at this point. (I was working on the drivers side andwas able to get it out without moving the steering shaft)
Before going anywhere, make sure that nobody will be messing with that floorjack!
Taking apart the arms;
The control arm is on the ground and what we are going to do now is removethe old (original) ball joint.
When the factory assembles the upper control arms, they use four rivets tohold the ball joint in place. This photo is a view from the top and if you lookclosely, 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 a4" grinder and decided to go that way.
Here the rivet heads have been ground off and it still didn't want to comeapart. What I found out is that the rivets had mushroomed out to the depth ofthe sheet metal cover plate (that upper plate that has the grease fitting). Ihad 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 thegarage. No magical numbers here, but I'd recommend that you go out and get apiece 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 thebolts 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 tocheck first. If you have to drill any holes in the arm for the bolts, you havethe wrong ball joint!
Take the ball joint and slide it into position in the spindle. The taper ofthe ball joint shaft should match the taper of the spindle exactly! If it doesn't, it'sthe wrong ball joint! While it's still there, make sure that there isn't anyproblem with getting the nut on. The shaft length should be the same length ofthe original ball joint.
Follow the instructions that came with the ball joint and attach it to theupper 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, rubberbushing, 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. Itwas 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 plusthe 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 wasto buy a complete cross-shaft "kit".
Although I didn't need an "offset" cross-shaft, they don't make astandard shaft anymore (for this installation).
I ended up measuring what the offset is and had to add shims when I put theassembly back into the car.
Another tangent is to explain what a "deformed thread" nut is. It'sa nut with slightly messed up threads that will not vibrate loose. (I wonder ifthere 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 toocolorful just make sure that you don't cock the bushings as you are trying todrive them in.
Start with installing one of the rubber bushings, without worrying about thecross-shaft.
When you install the other bushing, you have to make sure that you haveinstalled the cross-shaft and all the washers. If you don't do it correct, youwill have to trash one of the bushings in order to take it apart. Read theinstructions that come with the kit!
Install the deformed thread nuts and washers, but don't worry abouttightening 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 beeninstalled. 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 mountingbolts (studs). Thread the nuts onto the studs, but don't worry about tighteningthem yet.
Slide the ball joint shaft onto the spindle and install the nut. Tighten itdown "snug".
Reinstall the shims that you removed from between the cross-shaft and theframe. 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 lowercontrol 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 twocross-shaft nuts. It would be easy to walk away once the car is back onthe ground, but you would earn instant "jerk" status if you leavethese loose! You want to do this when the car is on it's wheels so that youdon't "preload" the bushings with a twist.
If you haven't had the alignment done in quite some time, it may be a goodidea to have it checked out.
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