Front Axle Installation - 410 Sprint Car Build
It’s time to install the front axle. First, we’re getting the radius rods assembled. We’re using aluminum heims in the aluminum tubes and steel heims for the left front radius rod and drag link. It's always a good idea to chase the threads to start. On the steel rods, there's a groove to denote left-hand thread.
People have different ways to install radius rods. One end has left-hand threads and the other has right-hand threads. This allows you to adjust their length without having to unbolt them. We had a discussion about which way to install the radius rods. In the end, we decided to put the right-hand thread towards the front and on the left side. This way, if the tire were to bump the rod, it would be tightened.
There are two holes in the pitman arm because they provide flexibility depending on what type of track you’re racing on. For example, on short tracks, drivers will want to steer quicker. On tracks like Knoxville, the driver would want to slow it down a bit to be less twitchy.
Now, we’re ready to install the axle. We’re working with a raised rail so we’re measuring the left side blocks at 3 inches and the right side at 4 inches. To have the most thread engagement possible, we’re starting out with the heims all the way in that way when you adjust them out you know you have the most thread engagement. Next, we can hook up our tethers and then it’s time to square everything. From the motor plate to the back of the axle is 46 1/4 for our car. Check to frame rail first to make sure the angle is zero degrees. The steering arm should be anywhere between 8-12 degrees. The way we’re squaring, the left is out one inch further than the right. There are different ways to measure toe, but as long as you measure off the same point in the front and the rear you will be good.
After squaring, it’s time to install the arms and bars. Some people choose to grease the whole bar in case it drags on the inside. We are only greasing the surface and a little beyond that. We’re leaving 1/16th inch of space to have some room for the bar to twist and tighten up. With the rack spacing, the long arm has to go to the left front. Grease can help prevent wear and tear between the arm and the axle. Were using caps to keep the arms in place in case the pinch bolts come loose.
The car is really taking shape. Thank you for following along with us and be sure to tune in next time!