How To Do an Alignment at Home | DIY Auto Alignment

Caster Explained

Caster is the angle of the steering axis when viewed from the side of the vehicle. This angle is achieved by tilting the steering axis either forward (negative caster) or backward (positive caster). Positive caster helps improve handling and stability at high speeds, creating a self-centering steering effect that is desirable in most street cars. Most street vehicles come with a preset caster angle, with adjustability typically available only through aftermarket suspension components. While positive caster angles might increase steering effort, the trade-off comes in enhanced straight-line stability and cornering precision at speed.

Camber Explained

Camber is the tilt of the tire relative to the vertical axis when viewed from the front or rear of the vehicle. When the top of the tire leans towards the inside of the vehicle, it is referred to as negative camber. This setup is common in performance-oriented vehicles because it provides greater lateral grip during sharp turns, allowing for quicker cornering speeds. On the other hand, too much negative camber can lead to increased tire wear along the inner edges of the tires and potentially reduced stability in straight-line driving. Adjusting camber requires careful balance to maximize cornering performance while minimizing tire wear over time.

Toe Explained

Toe refers to the angle at which the tires point inward or outward when viewed from above. If the tires point towards each other at the front, it’s called "toe-in"; if they point outward, it’s "toe-out". Toe settings affect tire wear and how the vehicle travels down the road. Toe-in increases stability and is often preferred for standard road vehicles as it helps the car to drive straight, reducing the effort needed to keep the vehicle centered. Toe-out, on the other hand, is used in certain performance settings to allow for quicker steering response.

Caster/Camber Gauge: There are several options available to measure caster and camber. The Longacre Caster/Camber gauge attached to the Longacre wheel adapter makes it quick and easy to get accurate readings. You can also find caster/camber gauges that mount with magnetic adapters for various wheel and suspension designs. There are ways that a basic carpentry level with some careful measuring and math can give you your caster and camber values, but the accuracy of a dedicated gauge is unmatched.

Toe Gauge: Toe can be measured with toe plates, or a string box can be built around the car. Off the shelf solutions are available to perform a string alignment, but you can also set it up yourself at home with minimal items to buy. Using toe plates like the Longacre Deluxe Toe Plates is a great way to set overall toe quickly, but it won’t give you your toe per wheel reading. To be able to measure each wheel’s toe individually, you will need to set up a string box. With toe plates you can get a measurement of 1/4-inch toe in, but one wheel may be 1/8-inch toe out while the other is 3/8-inch toe in, giving you that 1/4-inch total toe reading. Building a string box will ensure that the toe measured is the same at each wheel.

Turn Plates: When adjusting toe, the tire wants to do what it should, and sticks to the pavement. Turn plates allow the tire to move freely and ensures that the adjustment that you make when turning the tie rods won’t “spring” out of spec due to the tire binding. The lowest cost solution can be a pair of vinyl floor tiles with a bit of grease between them, which works, but not nearly as well as a set of turn plates with bearings to prevent the tire bind.

1. Ride height – If you have an adjustable suspension, make sure to set your desired ride height first. Raising or lowering ride height after setting your alignment will change camber and toe, so it is important to set this first.
2. Caster – This affects your steering stability and how well the car centers itself after a turn. Adjust by moving the upper or lower control arms, or upper strut mount, forward or backward to adjust to the desired angle. Using a caster/camber gauge, turn the wheels 20 degrees one way, zero out the gauge, then turn the wheels so they point 20 degrees the other way. The camber/caster gauge now reads what your caster setting is.

3. Camber – Adjust the upper or lower control arms, or upper strut mount, to adjust to the desired angle. Camber is important to set correctly to have even tire wear as well as desired handling. To get the camber reading, make sure the wheels are pointing straight ahead and place the camber gauge on the wheel. By making sure that the camber gauge is sitting level and flush to the wheel, you can now read your camber setting.
4. Toe – If toe is out of spec, you can experience accelerated wear that can quickly destroy tires. Adjusting the tie rods will move the front of the tire in or out. Once again, make sure that the steering wheel is pointing dead-straight before beginning, otherwise you might have a car that is driving straight down the road while the steering wheel points at 1 o’clock.

Before beginning your DIY alignment, you will want to check all the suspension components for wear and play. If you need to change a worn-out tie rod end, you will want to do so before a complete alignment. Tire pressures should be set, and you will also want to find a flat and level area to do your alignment. Many also like to simulate the driver's weight in the vehicle and have a half tank of gas on board as well.

A string alignment is a simple, yet highly precise way of setting up a car's toe and thrust angle. A DIY string alignment can be performed at home easily, and while it isn’t using the latest laser/computer alignment systems, it is a method used by many winning top tier race teams to get their chassis settings dialed in perfectly.

1. To accurately perform a string alignment, you first need to create a perfect rectangle around your car. The easiest way to do this would be to make two equal length straight bars with a hole drilled the same diameter as the string you will be using, as you don’t want the string to be able to move side to side. These holes are drilled the exact same distance from the edge of the bar for each hole. The strings are tied on one set of the bars, while the other end will get a weight attached to the string to keep it tensioned. These bars get clamped to a set of jack stands that are adjusted so the height of the string is in the centerline of the front and rear axles, and approximately 2” to 4” away from the tire.

2. Center the steering wheel and lock it in place with some ratchet straps or use a tool such as the QuickTrick 416474 Steering Wheel Holder/Alignment Tool. You want to make sure that the steering wheel is locked in the center position, otherwise you may find all your hard work needs to be redone at end.
3. To square up your strings, position the bars so the strings are exactly equal distance on each side of the car. Measure from the center of the wheel hub and slide the bar until the measurements are the same on both left and right sides. Keep in mind that most cars will have a different track width for the front and back, so it's important that the measurements are the same for each axle.

4. With the strings squared and the vehicle stable, you can now measure toe. At each wheel, measure the distance from the string to the front and back edges of the rims. Calculating the difference between these two measurements will determine your toe setting and if it is toe in or toe out. Make sure to consistently measure to the same side of the string as the measurement will be thrown off if you measure on the inside of the string on one side, and the outside on the other. Using a high-quality steel rule will be much more accurate than using a tape measure.

5. Adjust the tie rods to achieve the desired toe setting. If the front measurement is more than the rear, you have toe-in; if it's less, you have toe-out. Make incremental adjustments and re-measure until you achieve the correct front-end alignment.
6. After adjusting, it’s a good practice to roll the car back and forth to settle the suspension and then check the measurements again.

Aligning your car at home is a rewarding and cost-effective way to ensure optimal performance and tire longevity. While it may seem daunting at first, with the right tools and a methodical approach, you can achieve professional-level results. Understanding the key components—caster, camber, and toe—is crucial, Performance Tire Alignment Even Wear and following the outlined steps will help you perform an accurate alignment.

By learning how to do an alignment at home, you gain the flexibility to fine-tune your car’s suspension setup to your specific needs, whether you're preparing for a race or ensuring your daily driver handles smoothly. Plus, you'll save money and avoid the hassle of finding a shop willing and able to work on your unique vehicle.