shogun
01-04-2013, 07:49 AM
There are two ball joints on each control arm of a 3 series car. If you have a bad ball joint on an E30 you will need to replace the control arm as a complete unit, this does not come with a new rear bushing or bracket, so now is the time to change your bushings also.
E36 vehicles do not require replacement of the control arm if the outer ball joint is bad, if the inner one is bad, you must replace the complete control arm, again, the rear bushing and bracket are separate.
To determine if the ball joints are bad on an E30, squeeze them with a large pair of pliers, there should be no vertical movement. This method also applies to E36 inner ball joints. E36 outer ball joints will show vertical movement even when brand new, this cannot be used to gauge their condition.
The outer ball joints on E36's have a different design, the ball joint is housed in rubber and molded into a bracket which is pressed into the control arm, this allows vertical movement , using the rubber as a dampener. If a ball joint is very bad, you will be able to move the wheel horizontally, in and out. Another sign of a bad joint is the rubber separating from the bracket mounted in the control arm. Early versions of the E36 have a habit of tearing the rubber insert out of the bracket, it cannot actually separate from the control arm, but allows the rubber mount to turn inside the bracket, rather than the stud turn inside the ball joint. This problem was rectified by a production change that modified the ball joint , giving it two metal ears that prevented the rubber section from turning inside the bracket, which was causing the rubber to tear out of its mount.
In the case of an outer E36 ball joint, it may work out considerably cheaper to take the car to a dealer. The process requires a special press that is used on the car, some well set up independent repair shops will also have this press, but most will try to sell you a complete control arm. The ball joints cost less than $30 US on average, and you should not pay more than 1.5 hours labor to change BOTH left and right outer ball joints.
Replacing a complete control arm
Unless you have a vice, remove the control arm bushings on the car. If you have a vice, use the same procedure above to remove the bushings, but do it after removal of the control arm.
Undo the nuts on each ball joint. The nuts on the inner ball joint can be very difficult to remove, as they tend to break loose the stud in the ball joint, allowing it to turn as you turn the nut, so you can be undoing the nut for hours without it moving on the thread. Try to prevent this from happening before it starts, by placing a jack under the ball joint and putting upward pressure on it. Do not use this jack to support the vehicle.
As you are not reusing the control arms, the ball joints can be removed with a ball joint fork and hammer. This method destroys the boot on the ball joint , but is by far the easiest way of removing them.
Installation is the reverse of the removal. If you are installing the rear bushings off the car, align the bushing bracket with the forward arm of the control arm. They must be on the same plane to correctly pre-load the bushing.
Source: Koala Motorsport Tech Tips
E36 vehicles do not require replacement of the control arm if the outer ball joint is bad, if the inner one is bad, you must replace the complete control arm, again, the rear bushing and bracket are separate.
To determine if the ball joints are bad on an E30, squeeze them with a large pair of pliers, there should be no vertical movement. This method also applies to E36 inner ball joints. E36 outer ball joints will show vertical movement even when brand new, this cannot be used to gauge their condition.
The outer ball joints on E36's have a different design, the ball joint is housed in rubber and molded into a bracket which is pressed into the control arm, this allows vertical movement , using the rubber as a dampener. If a ball joint is very bad, you will be able to move the wheel horizontally, in and out. Another sign of a bad joint is the rubber separating from the bracket mounted in the control arm. Early versions of the E36 have a habit of tearing the rubber insert out of the bracket, it cannot actually separate from the control arm, but allows the rubber mount to turn inside the bracket, rather than the stud turn inside the ball joint. This problem was rectified by a production change that modified the ball joint , giving it two metal ears that prevented the rubber section from turning inside the bracket, which was causing the rubber to tear out of its mount.
In the case of an outer E36 ball joint, it may work out considerably cheaper to take the car to a dealer. The process requires a special press that is used on the car, some well set up independent repair shops will also have this press, but most will try to sell you a complete control arm. The ball joints cost less than $30 US on average, and you should not pay more than 1.5 hours labor to change BOTH left and right outer ball joints.
Replacing a complete control arm
Unless you have a vice, remove the control arm bushings on the car. If you have a vice, use the same procedure above to remove the bushings, but do it after removal of the control arm.
Undo the nuts on each ball joint. The nuts on the inner ball joint can be very difficult to remove, as they tend to break loose the stud in the ball joint, allowing it to turn as you turn the nut, so you can be undoing the nut for hours without it moving on the thread. Try to prevent this from happening before it starts, by placing a jack under the ball joint and putting upward pressure on it. Do not use this jack to support the vehicle.
As you are not reusing the control arms, the ball joints can be removed with a ball joint fork and hammer. This method destroys the boot on the ball joint , but is by far the easiest way of removing them.
Installation is the reverse of the removal. If you are installing the rear bushings off the car, align the bushing bracket with the forward arm of the control arm. They must be on the same plane to correctly pre-load the bushing.
Source: Koala Motorsport Tech Tips