This set up is not something I would have normally considered but I am in the unique position of upgrading from the factory control arms, and I already have geometry correction brackets installed.
What do geometry correction brackets do?
For some of you this is going to be very elementary information. Feel free to skip ahead. For those of you who may be new to the off-road world or simply want to learn more please read on!
The explanation is in the name. Geometry correction bracket. These are parts that bolt into the factory control arm frame mounts and alter the mounting location for the control arm.
I currently have the TeraFlex brackets, and the control arms are almost perfectly flat when installed with a 3.5-inch lift.
Why is this a good thing?
The flatter your control arms are the better they can “control” the axle movement. Think about holding onto a rope or pushing a cart. It’s easier the straighter your arms are.
If you compare the two images in this section you can see a big difference in the control arm angle. Even though the bottom image is a 1-inch taller lift the control arms are much more level and in line with the axle. (The ground angle is opposite so both arms do point down to the axle.)
Moving the pivot points lower keeps your axle in line vertically for longer. This is a hard concept to think about. On any solid axle vehicle, the axle does not move up and down in a straight line. It travels on an arc. If at the vehicle ride height you are already in the lower part of the arc, the axle will move more rearward when your suspension is drooped out.
The flatter control arm also makes for a smoother ride. When your control arms are pointed down at the axle some of the force from hitting bumps is transmitted through the control arm adding stress to bushings and transferring that into the chassis.
When the arms are flat, that force is handled almost completely by the spring and shock with little to no force from the bump traveling through the control arms. That’s less wear and tear on the vehicle and the driver.
Why should I use them with aftermarket control arms?
I am not saying you should or shouldn’t. What I am saying is it will improve your suspension geometry and improve the performance of your vehicle off-road.
Aftermarket control arms are usually adjustable, they are stronger, have better joint movement, and almost always result in more suspension flex.
In my case I am running the TeraFlex Alpine Arms with their new Independent Rotation (IR) bushings. They can be torqued at any angle and still allow the arm to move through its full range of motion. This is due to the outer rubber bushing being able to rotate around the center steel tube. Check out the little GIF below from a previous article.
Take all of those benefits and add to that optimum control of the axle and you can’t help but get excited about how it should all work.
What are your thoughts?
Am I crazy? Would you spend more money to run both?
It won’t help you win any RTI bench racing. The gains will only show up on the trail when you have an easier time locating your wheels, and you aren’t fighting axle steer on obstacles.