Trucks with 4×4 are rugged machines that need some more acceptable tuned parts and components to keep them capable of tackling off-road adventures. The average commuter car doesn’t need its rear wheels aligned. However, some truck owners with 4×4 vehicles may wonder if a rear-wheel alignment is necessary.
Trucks with four-wheel drive require rear wheel alignment. This sort of alignment for the rear wheels has four measurements of the:
- Thrust angles
Trucks with four-wheel drive are excellent vehicles for many purposes. They work hard, and owners should take care of their trucks so that they can continue delivering the payload for work or take on any obstacle they come across on the trail. Read on for more information about why trucks need a rear wheel alignment and how this rear wheel alignment gets done.
What is Rear Wheel Alignment on Trucks?
Trucks that have four-wheel drives need a rear-wheel alignment. Rear wheels also get adjusted with alignment. There are more options and combinations of alignments for your vehicle than you would typically get with a two-wheel-drive vehicle.
Rear-wheel alignment on trucks is necessary because 4×4 trucks typically have adjustable rear suspension. You must bring all the tires into the specification outlined by the manufacturer, or at least balance out the car’s alignment so it drives straight with minimal drag.
The correct alignment gets measured in degrees of:
- Camber (tire leaning inward or outward)
- Caster (front-down slope of wheel components)
Performing regular wheel rotations can make the tires last longer on the road.
The center of your vehicle is the anchor point that all four wheels get aligned to. The centerline as the anchor point for the back tires is different than a two-wheel-drive car where the rear wheels align with the front two wheels. The process of aligning the rear wheels on a truck is pretty straightforward.
We will list them in simple steps below based on the four different components of the rear wheel suspension and assembly.
The first measurement for rear-wheel alignment deals with the camber of the wheel. Camber means the suspension angle of the tire with 0 degrees being neutral or no angle to the tire.
If your tire is in a negative camber position, this means that it shows the top of the wheel that tilts downwards towards the center of your vehicle. A positive camber position implies the top of the tire is angled up and away from the center of your vehicle and axle.
Camber is usually not touched for four-wheel-drive vehicles. In other words, you want it in a neutral camber position. However, suppose the outer or inner rib of the tire is wearing out quickly. In that case, these wear patterns could indicate the camber being out of alignment.
The steering pivots points are called the caster of the tire alignment. This measurement is best described as the angle from the suspension design’s lower and upper ball joints (wishbone or A-arm) or the lower ball-joint and strut tower mount to a perpendicular line angled to the ground.
Adjusting the caster on the tires also allows for positive and negative positions of angles.
- Positive caster means that the perpendicular line formed by the ball joint and the ground gets positioned back towards the rear of the tire.
- Negative means that the line is angled forwards towards the front of the tire.
Caster adjusts the tire back and forth. A tell-tale sign of a problem with the alignment of the toe measurements is if there is visible scrubbing or wear across the center of the tire tread.
By identifying the truck’s centerline concerning the direction the tires get pointed when viewed from directly above, you measure the tow adjustment. The two positions to look out for with toe are “toe-in” and “toe-out.”
- A toe-in angle measurement means that the front edge of the tire is pointing towards the truck’s center.
- A toe-out angle measurement indicates that the tire face is pointing away from the center of your truck.
Usually, the toe measurement angle is a measurement tool used for helping fix the suspension bushings which might be out of alignment. Toe adjustments are also a great way to make handling more efficient and give your truck a better feel, especially if you take it off-roading.
The thrust angle is the measurement that tells you if the rear axle is parallel with the front axle. If your thrust angle is off, it could cause the frame to get bent and may need professional straightening of the solid rear axle and frame.
Thrust angle is measured in degrees and is an essential part of 4×4 truck maintenance, especially if you have a solid rear axle and wheelbase.
Here’s an informative video showing how to tell if you need an alignment:
Front-End Alignment vs. 4-Wheel Alignment vs.Thrust Alignment
Two-wheel drive vehicles only likely need alignment at the front. However, four-wheel-drive vehicles need alignment in the rear occasionally, as well. The benefit of wheel aligning includes securing optimal driveability and saving energy from fuel waste.
Front end alignment is only the front two-wheel alignment, whereas 4-wheel alignment includes the rear wheels. If the truck doesn’t have a rear suspension system, thrust alignment is necessary during 4-wheel alignment.
An explanation of these three essential alignments follows. Keep in mind that the front-end alignment is priority number one. Rear-wheel alignment should come after the front is aligned correctly, or you could damage the frame of your truck.
The front end has only the front two wheels aligned for its maintenance. It is the simple first step in maintaining the balance of your truck. The front two wheels get adjusted for caster, camber, and toe.
- The wheels at the front need to be parallel and straight with the centerline of the truck.
- Otherwise, the wheels could cause damage to the frame of the truck while driving, especially if you frequent off-road trails and roads.
This simple alignment is usually not recommended as the only part of maintenance for more contemporary trucks since the service does not include a look or maintenance on the angles of the truck’s rear end. The rear end must also be in alignment with the front end for the truck to work in perfect balance and symmetry.
Therefore, front-end alignment is only the first step in complete truck wheel maintenance.
Some of the contemporary models of trucks have independent suspension on each wheel. This separate suspension system is great for a smooth ride. Still, it also makes alignment and balancing a little more complicated.
A four-wheel alignment is required for trucks with independent wheel suspension so that each wheel is serviced individually and balanced with toe, camber, and caster for the perfect symmetrical angle from its position on the truck body.
The rear axle angles are measured first and then the front axle angles. This ensures that the wheels are angled and balanced to the centerline of the truck.
Thrust alignment is used on a truck with a fixed rear suspension or a solid axle on the rear. Since the rear wheels are not attached to independent suspension, they get aligned as near as the technician can get them to the thrust line where the two rear wheels are pointed.
- The measurement of the angle of the wheels towards the thrust lines allows for offsetting the difference between the wheels and centers of the steering.
- Thrust alignment is great for tightening up the handling on your truck and making it a little more responsive.
How Do I Know When I Need a Rear Wheel Alignment?
Rear-wheel alignment is a part of the maintenance of your truck that should not be ignored. Even though a check engine light may not come on for tires that are out of alignment, some signs should tell you that it is time to get your truck into the shop and have the rear tires appropriately aligned by a professional.
Some indications that the rear tires require alignment are if the handling is loose or choppy, if the tires are wearing improperly, or if your truck is drifting or pulling to one side when you take your hands off the steering wheel.
Even though these signs are usually obvious, many people decide to forgo getting their rear tires aligned until it is too late. If you drive with the wheels out of alignment, you can do severe damage to your:
- Tire systems
- Frame of your truck
Below are some of the details you need to know about the different signs that your truck is in need of a rear-wheel alignment. Hopefully, you can use this information to identify the needed maintenance on your tire alignment before it is too late.
Drifting and Pulling
A truck that is drifting to one side or pulling when you are trying to keep the wheels straight is a dangerous sign that your tires are out of alignment.
Usually, the rear tires are the ones that tend to cause the pulling or hard yanking of the direction that the car is going in.
The pulling on the steering wheel can be checked, but only at low speeds by taking your hands off the wheel momentarily and noting which way that the car is drifting.
Giving this information about the direction that the truck is pulling is invaluable for the service technicians so that they can get right to work identifying the angles of the tires and properly get them dialed in on the centerline of your truck.
Feeling vibrations or choppy handling that seems like the truck could go out of control is not only scary and dangerous, but it is fixable. The alignment of your rear tires could be the culprit and should be checked for camber and caster alignments immediately.
- Choppy handling feels like you are on a rocky or rough road, even when you are not.
- This loss of handling or choppy handling might be most noticeable at high speeds or when you are turning.
Ensure that you get your truck in right away when you begin feeling choppy handling that feels like the truck might pull out of control. This is a dangerous condition for your truck and is damaging the truck components and frame with each drive that you take.
Choppy handling is one of the signs that you may need to take your truck to the body shop and get the frame straightened.
Improper Tire Wear
Tires that wear out too quickly or have specific tire wear patterns are an easy indication that the alignment is off on your truck. The alignment causes certain parts of the tire’s rubber to meet the ground.
However, when tires are balanced all around your car, the wrong surface of the rubber gets worn out.
Some of the tell-tale signs that the tires are wearing improperly are:
- Wearing strips across the tread lines
- Intense wearing along the inner or outer rim line
These indicate that the tire or tires are wearing unevenly and need alignment throughout the four wheels of your truck.
Even though we often drive without thinking about our tires, visual inspection on a regular basis is always a good idea. Make sure that you check the tread and tire wear of your truck continually so you learn the patterns. Especially check the tire wear patterns if you feel a vibration, choppy handling, or pulling and drifting on your truck.
Trucks are workhorses on the road and trail, but even this pickup tool needs some TLC once in a while. The rear wheels on a truck need alignment with the three and maybe even four types of measurements that the alignments of tires depend on.
If you have a truck and notice any obvious signs of wear, handling, or pulling that indicate your truck’s wheels are out of alignment, don’t delay and immediately get your truck into a body or tire shop. Doing so could save you money and the headache of driving a damaged truck in the long run.