Do you want negative or positive caster?

Caster is said to be positive if the line slopes towards the rear of the vehicle at the top, and negative if the line slopes towards the front.

Is it better to have negative or positive caster?

Performance Benefits of Positive Caster

You get better handling when cornering, better stability at high speeds, and better straight-line tracking. The better traction while cornering is similar to a vehicle with negative camber, as it keeps more tread on the ground despite the sharp angles.

What does too much positive caster do?

Caster settings are not a primary, direct factor in tire wear. However, excessive positive caster in association with other alignment maladjustments can exacerbate a tire wear issue. For example, a tire wear pattern called feathering can result from a combination of too much caster with incorrect toe settings.

What is a good caster angle?

Generally you want as much positive caster as you can reasonably get so long as the car is equipped with power steering. Positive caster angles run between 3 - 5° on modern vehicles. This gives a good mix of highway stability and steering feel.

How does negative caster affect handling?

Negative caster results in lighter and easier steering but reduced stability when driving in a straight line. Vehicles with negative caster do not handle as well. What is this? A symptom of negative caster is a sloppy or loose-feeling steering wheel (which is lot less common than a hard to turn wheel).

How Caster Works

What is better toe in or toe-out?

Generally the rule of thumb is that more toe-in increases understeer and more toe-out increases oversteer. However, with modern cars, especially race cars with independent front and rear suspensions, there is another effect on handling.

Should caster be the same on both sides?

As a rule, caster angles should usually be within half a degree or less of each other side-to-side. If there is a greater difference in caster angles side-to-side, it may cause the vehicle to lead or pull toward the side with the least positive caster, or the most negative caster.

Will caster cause a pull?

Poor camber and caster alignment can cause your vehicle to "pull", and can cause tire tread to wear unevenly. Toe in won't cause your vehicle to pull, but it can cause extremely fast tire tread wear.

Can too much caster cause death wobble?

If your Jeep has too little caster angle, it can be a candidate for developing death wobble. As always, too much of a good thing ain't bad. Add too much caster angle and your Jeep will wonder down the road like it's lost as the two tires fight to follow their own independent path.

How does Castor affect steering?

Caster angle settings allow the vehicle manufacturer to balance steering effort, high speed stability and front end cornering effectiveness. Increasing the amount of positive caster will increase steering effort and straight line tracking, as well as improve high speed stability and cornering effectiveness.

Does changing caster effect toe?

If they are toed out too much, the wear will start from the inside of the tire. This type of wear is called feathering. Caster, on the other hand, has no effect on how a tire wears, but it does play a role in handling and on center feel.

Does caster affect ride height?

Ride height can also affect caster. Spring sag or overloading a vehicle can alter ride height up to several inches, which can increase caster readings by up to a degree or more.

What is negative caster?

Negative Caster - If the line slopes towards the front of the vehicle then the caster is negative. Negative caster will allow you to steer less around turns, but may cause you to drift if you are driving straight forward.

What does caster do for drifting?

Caster really helps a drift car by making it self-steer better. When you start to drift, you can simply let go of the wheel and let if feed through your fingers, and the car will counter faster than if you were steering it yourself. Caster also gives you more negative camber as the wheel turns, which helps front grip.

Does negative caster cause a pull?

It's formed by a true vertical line and a line through the center of the vehicle's strut. It's the forward and backward tilt of the steering axis as seen from the side of the vehicle. If the caster is not equal on both sides of the vehicle, it will pull to the side with the least amount or most negative caster.

Does positive caster cause pull?

As far as we know, all four wheel vehicles are designed with positive caster (forks out towards the front at the bottom). So we are talking about more or less positive caster. Camber may pull toward positive (more tilt in at the top) but caster will pull toward negative, or less caster.

Can you have too much caster?

You can never have too much caster!!

Increase directional stability. Maximize tire contact patch during braking and acceleration.

How does rear toe affect handling?

Toe adjustments on the rear tires also have an effect on car handling. Toe-in on the rear creates understeer, which can help with cars that are oversteery on exit. The tradeoff is wear and heat in the rear tires. Toe-out on the rear is generally wrong, as you're likely to get more oversteer on exit.

Do you adjust caster or camber first?

With front-end alignments, correct caster and camber adjustments first. Certain FWD vehicles do not offer caster adjustments, but correcting the camber may bring the caster within specs.

What does castor do in alignment?

Caster causes a wheel to align with the direction of travel, and can be accomplished either by caster displacement or caster angle. Caster displacement moves the steering axis ahead of the axis of wheel rotation, as with the front wheels of a shopping cart. Caster angle moves the steering axis from vertical.

Is negative toe good?

What is this? Front-wheel drive vehicles use negative toe-out to avoid forward movement and enable tires to move side by side at a relatively good speed. Excess toe-out can cause the inside edges of tires to wear out quickly, braking issues, and understeer issues.

What should toe be set at during alignment?

Typical toe-in specs vary from one-thirty-second to one-eighth-inch, depending on the vehicle. Check a service manual for your car's acceptable range. The best tip-off to a toe problem is a saw-tooth wear pattern that's equal on both front tires.

What is the importance of toe out on turns?

The angle of the steering arm on the steering knuckle determines the turning radius. It's known as the Toe Out On Turns or the TOOT angle. This angle keeps the front tires from squealing around corners.

What causes bad caster?

It was common in older vehicles that don't have power steering to help lessen the steering effort. Negative caster improves steering but diminishes handling and stability when driving in a straight line. A vehicle that pulls to one side when moving in a straight line may have a negative caster.