Update 11-06-2013: Added a video at the bottom of the page. Also updated the article to include all three of the front control arms.
This guide will show you how to replace the lower rear control arms on your Mazda 6. Normally a control arm replacement is easy - couple of bolts and you're done. Not in this case. In order to remove one of the control arm bolts you will have to lower the rear of the subframe a little so that the bolt clears the frame of the car. There is a little more work involved but it's still not too bad of a job.
Applies To: 2002 - 2008 Mazda 6, 2006 -2009 Ford Fusion & Mercury Milan
How To Remove the Front Lower Rear Control Arm
1. You should have the car up on jack stands and the wheel removed.
2. First thing you have to do is loosen the control arm bolt on the right. Then you have to remove the control arm nut on the left. Because let's face it, you don't want to lower the sub-frame and then find out that you can't remove the bolt & nut from the control arm. You won't be able to remove the bolt completely until you lower the rear of the sub-frame. You will also want to separate the control arm ball joint from the steering knuckle. You can use a ball joint separator to do this. Be careful when using the separator, you do not want to damage the other ball joint. You can also use a hammer and knock it out from the bottom but, again, be careful - the steering knuckle bushing will most likely come out with the ball joint.
If that happens, you can use a jaw puller and separate the two pieces.
3. You will need to disconnect the steering gear from the steering shaft inside the car. Why? Because the steering gear is connected to the sub-frame so when you lower the sub-frame it can do some damage to the steering shaft - unless it is disconnected. Look under the driver's side dashboard. You will see the cover for the steering gear u-joint. Remove the two plastic nuts and pull up on the cover.
4. With the cover out of the way, mark (index) both the gear and the shaft so that you know how to install them later on. Once that is complete, remove the bolt and slide the steering shaft up. Set it out of the way.
5. Pull back the insulation material and take out the rubber seal (green). It is clipped in place so you may have to push from the other side.
6. Position a jack under the rear of the subframe. This will provide support as it is lowered.
7. You'll want to disconnect the left cover from the subframe. You probably don't have to do this as it is only going to be lowered a couple inches at most, but better safe than sorry. Do the same thing on the other side.
8. Remove the one nut and two bolts from the sub-frame-to-body bracket. Do the same on the other side.
9. Using the jack, lower the rear of the subframe just a little, enough for the bolt to clear the frame of the car. Remove the control arm.
Installation of The Front Rear Control Arm
1. Position the new control arm inside the subframe and tighten the bolt to 48 lb-ft. You will need to tighten this another 90 degrees once the suspension is in neutral position. If you fail to do this, once you lower the car, the control arm is going to rotate and put a lot of stress on the new bushing. Insert the other end of the control arm (the ball joint) inside the steering knuckle. Tighten the new nut on the ball joint to 148 lb-ft.
2. Raise the sub-frame back up and install the metal brackets. The big nut should be torqued to 111 lb-ft and the two smaller bolts need to be torqued to 76 lb-ft
3. Install the steering gear seal and connect the steering gear to the steering shaft. Make sure the index marks line up otherwise your steering wheel is going to look jacked up. Tighten the bolt to 15 lb-ft. Reinstall the steering u-joint cover - finger tighten the two plastic nuts.
4. Secure the plastic covers at the wheel wells (if you removed them).
5. The final step is to tighten the control arm bolt an additional 90 degrees. You have to make sure the suspension is in the neutral position before you do this. If you fail to do this, once you lower the car the control arm is going to rotate and put a lot of stress on the bushing. So grab a jack and push up on the knuckle to compress the suspension. The suspension is in neutral position when you have 15.83 inches between the bottom of the wheel well and the center of the wheel hub.
6. Install the wheel and triple check to make sure you tightened everything. The last thing you need is a control arm falling off in the middle of your commute. The end.