Wheel Alignment, Procedures Options

[r_towle]

I would like to get a classic thread here...so please lets keep it focused.

With a string box, please describe the process for doing a 4 wheel alignment in the home shop..

To set up a string box, I do the following.

Using either milk crates, cinder blocks, or jack stands...

Create a rectangle of string around the car.
Measure from the centercap of each wheel to ensure that the box is parallel to the sides of the car. It does not have to be square, nor does it have to line up with the front or rear of the car.

The string lines need to be parallel, and have the same distance from each wheel center. the string should be at the same height as the centerline of the wheel.

Once the box is set up, you can measure from the front and rear of each wheel (not tire) to the string, write these numbers down for each tire.

The steering wheel must be straight and lines up as you would like it to drive...for those of you that have a wheel that is already cockeyed...turn the wheel to where you would like it to be when driving straight...

Now with all your measurements, you need to adjust the wheels so that the front of each wheel is 1/16th of an inch longer measurement from the string than the rear of the wheel.

This will give you an overal 1/8 inch toe in.
If you steering wheel is not straight, you will need to fix that first.

To change the toe in the front, you will loosen the locking nut on the tie rod, and turn the tierod either in or out...this will set the front toe...if you need to fix the steering wheel position, you basically need to loosen one tie rod, and tighten the other..all the time you will be getting up to check the steering wheel location.

that is the front, dont forget to tighten the locking nut when you are done.

Now the rear...I am a bit foggy...so someone please describe setting toe in on the rear.

Rich

[lapuwali]

When measuring front toe, it's actually quite difficult to get the steering exactly centered. It's more accurate to take 2-3 measurements with the steering turned to the right and left and average them to get the "centered" result.

When using the wheel rim, you have to ensure the wheels don't have too much runout, which can throw off the measurements. Perfectly acceptable wheels often have 1-2mm of runout at the rim. Using the straight pin in the tire tread and rotating the wheel (as I described the last time this came up) is actually more accurate than using the wheel rim.

Trying to get the lines parallel by measuring the distance from the hub assumes the front and rear track are the same, which they aren't on the 914. The factory measurements for track are 58.2" front, 57.1" rear. Front and rear track are commonly different on many cars. This isn't a problem as long as the hubs at each end of the car are the same distance from the centerline. Using your method, the strings along the sides of the car would not be parallel to each other, or the centerline of the car. They would diverge towards the front, which would substantially throw off your toe measurements.