Suspension alignment

[jkg2101]

Next I want to set the long axis of the rear tires to be parallel to this long axis of the frame. The tape marks on the ground show me the long axis of the frame. I need to determine the long axis of the tire. I came up with an idea to use string under tension, although others have apparently also used this from what I hear.

I put a heavy jackstand behind the car, towards the center, and a second in front of the car. I tied a string between those jack stands, so the string is coming from inside the back of the rear tire and running toward the front. The string should be under tension, not loose, so it is a straight line. Then I move the front jack stand so that the string is just barely touching the front of the rear tire, so I know the string is along the axis of the rear tire. So now the string is perfectly parallel to the long axis of the tire.

I then adjust the toe of the rear tire until I can get the string to be parallel to the frame axis, which is on the floor on the green tape marks. The rear toe-rod (probably the wrong name) is easy to turn to make this adjustment. My floor is vinyl tile, and if I put a thin piece of cardboard under the tires, the wheels slide easily, so I can move the tire and not have to rock the car to be sure the tire has moved. If I was on pavement or unfinished concrete, I would have to rock the car back and forth a bit to settle the tire to be sure the change in the suspension is in effect. Hope that makes sense.

At first, I set the rear toe to be “zero.” This helps align the front tires later. Even later on I will add toe in.