Tech Talk Sprint Car Rearend Squaring
Jason Martin shares his 15+ years of experience to help racers learn how to square the rear end of a sprint car. Rear axle assembly can be difficult, but Jason is here to help simplify the process.
To begin, set the rearend on six-inch blocks, then make sure the car is level. Place your level at the front of the car, close to the motor. Once everything is level, use a wide, strong tape measure to make sure that the rear axle is 38 and 5/8 inches on the right side. This is the standard measurement, but some cars may vary slightly. Then, follow the same steps on the left side. The most important rule for squaring a car is that the back axle is square to the motor plate, and the front axle is squared to the motor plate.
Once those steps are completed, it’s time to level the birdcages. Since your frame is level, put the angle finder on top of the Eagle birdcages where it's flat. Rotate it until it’s in between zero and two degrees. Then take the bolt from the lower birdcage flag and put it through the heim. You can rotate the heim to adjust if needed.
A great way to double check that everything is set correctly, is to make sure that the rear arm and torque ball move freely.
The next step is to set the jacobs ladder length. Rotate the jacobs ladder up, to see if the pin fits. If it doesn’t, rotate the heim until the pin easily slides in.
After that, measure one final time to ensure accuracy. Triple check with the angle finder and feel that the rear arm and jacobs ladder move freely. Then, tighten the jam nuts for the radius rods, rear arm and jacobs ladder. Finally, screw in the bolt for the stop on the bottom of the birdcage flag. We hope this video was helpful! Thanks for following along!