The NASA-permitted Bauer ball joint is extended outward to allow for more negative camber adjustment without having to lower the car more, at which point the shocks hit the bump stops.
Before the rules changed, the only way to get more negative camber from the front suspension on a Spec Miata was to lower the car. It worked, but it also could put you down into the bump stops in hard cornering and abrupt suspension moments such as driving over kerbs.
Changes in the Spec Miata rules now allow the use of offset upper control arm bushings in the front and the Bauer Suspension extended lower ball joints. Both options allow for more negative camber without having to lower the car more.
NASA rules allowed the lower ball joints first, and that’s what I used on my last car, so I elected to go with them again in my new build. I still believe they’re easier to install than upper bushings, because I don’t own a press and there’s really no way to install the ball joints incorrectly. The upper control arm bushings require a press and their offset bolt holes must be perfectly aligned with each other for the suspension to function properly.
Unlike bushings, the ball joints have moving parts, so they do wear out. I got two and a half seasons out of the last set, but they should have been replaced after two seasons. If you have significant contact, you might consider replacing them, too. We found the problem when doing an alignment. With the front wheels off the ground, the wheel exhibited vertical play. On the track, the slop made it difficult to transition smoothly from yaw at corner exit.
The job itself should be fairly self-explanatory as you pull things apart. It’s possible to do the job without removing the front rotor or caliper. The ball joint can be a bear to detach from the lower point on the steering knuckle. A ball-joint separator tool or a big freaking hammer are vital tools for this job. Here’s how it went.
The first thing to remove is the lower attachment point for the sway bar end links. It creates more room to work. Depending on whose end links you have, it’s usually a 14 mm nut and bolt.The lower shock mount also has to come off because one of the bolts that attaches the ball joint is located under the shock on the control arm.A lot of times the shock bolt won’t come out by hand, so a few taps with a punch or a drift pin will do the trick.Remove the cotter pin from the lower ball joint and remove the nut that holds the ball joint to the steering knuckle. My impact wrench didn’t have the torque, so I had to use a big breaker bar.You can use a ball-joint separator to pop the press-fit ball joint loose from the steering knuckle. A lot of times, a few blows from a hand sledge on the threaded shaft of the ball joint is enough to jar it loose.There is a horizontal bolt that runs fore and aft on the lower control arm. Use a 17 mm impact and a box wrench on the nut on the other side to remove the bolt.In the “pocket” under the lower shock mount, there’s a vertical 17 mm bolt that holds the inside end of the ball joint. Pop it loose with an breaker bar.Once you’ve broken it loose with the breaker bar, use a cordless impact to spin the bolt out quickly.I had to replace the extended ball joints on my last car and they were more difficult to remove than the factory ball joints. I used antiseize lubricant in anticipation of having to replace these ball joints.This shot shows the ball joint’s inner attachment bolt inside the shock mounting “pocket” in the lower control arm. To get the bolt threaded into the new ball joint a little more easily, be sure to install the outer bolt first.It makes things easier to use a block of wood and a floor jack to raise the lower control and the ball joint up and through the hole in the steering knuckle.I was not comfortable driving the ball joint nut on with an impact wrench, so I used a half-inch ratchet and the 22 mm socket to gently squeeze things into place.The torque spec for the ball joint castle nut is 57 foot-pounds. Of course, at 57 pounds, one of the spires on the castle nut blocked the opening for the cotter pin, so I turned the nut just a bit more to open up the hole so the cotter pin would go through. Add the cotter pin, bend the tangs and do the other side.
