• 2019

Steering Clear of Steering Problems

While the reliability of the modern automotive vehicle — be it sedan, minivan, SUV or pickup truck — has increased dramatically over the last 25 years, routine maintenance is still important. Over time, some parts still wear out, but even those that do are now lasting longer due to better materials and enhanced lubricants. Nowhere is this more evident than in the steering system.

Lower ball joints and outer tie rod ends are the main culprits. Since the vast majority of vehicles have McPherson strut-style front suspensions, there are fewer parts that wear out (for example, no upper ball joints, inner tie rod ends and steering arms) sooner. For the purpose of this article, our sample vehicle (the 2012 Chrysler 300 built on the LX chassis that has been around since 2005) will be used to demonstrate repairs. This chassis has lower and upper control arms, which brings a second ball joint on each side of the vehicle (another wear item).

The development of advanced materials has resulted in ball joints and outer ends that do not require lubrication. But how do you determine if these parts have exceeded their normal service life and what effect it has on steering performance? We’ll also discuss wheel alignment in this article.

Steering Basics

The LX body has two drive versions: (1) rear-wheel drive (RWD) and (2) all-wheel drive (AWD). Both versions use a rack and pinion steering system. This is a simple system in which the steering wheel column is attached to a pinion gear that is meshed with a flat rack gear. As the steering wheel is turned, the pinion gear moves the rack gear in the direction of movement. Tie rod ends attached at each end of the rack and the steering knuckle for each wheel move the wheels so the vehicle can be steered in the desired direction.

The design of the front suspension determines the caster (tilt of the wheel from front to back) and camber (tilt of the wheel from side to side). These two parameters determine how the vehicle tracks as it is driven. They also influence tire wear. Toe has a greater influence on how the vehicle tracks compared to camber and caster. On most modern vehicles, camber and caster are set at the factory. Only toe is adjustable. On the LX models, camber and caster can be adjusted with the installation of a special adjustment bolt (more on that later).

Steering Problems

Steering problems are not always the result of worn steering and suspension components, or incorrect alignment settings. If the vehicle leads or pulls in one direction, get the vehicle out for a road test. To accurately evaluate the vehicle, drive the same road in both directions to get a feel for the effects of road crown and cross winds. A neutral vehicle will exhibit a small amount of drift on both the right and left crowned roads. If the vehicle has pronounced lead/pull, check for the following conditions:

  1. Unequal Tire Pressure – tire pressure must be equal in each tire; a noticeable difference in the front tires will cause the vehicle to lead/pull in one direction.
  2. Tire Conicity – this is a defect in the making of the tire that causes the vehicle to pull in one direction; cross switch the front tires; if the vehicle still pulls in the same direction, return the tires to the original position.
  3. Check The Suspension Alignment – non-symmetrical front caster or camber can sometimes cause a lead condition; usually, these two parameters do not change during normal driving and cannot be adjusted; however, an accident or chassis damage can cause these parameters to change.

Steering issues can also be the result of incorrect toe settings, which is the most common alignment parameter that changes. There are two reasons that cause toe to change: (1) normal driving and (2) worn tie rod ends.

Worn Tie Rod Ends

Worn outer tie rod ends are the most common cause of wheel alignment and steering problems. If the outer ends are worn, it is nearly impossible to correctly align the vehicle.

The most accurate method to determine if the outer tie rod end is worn is to measure, with a dial indicator, the amount of vertical movement.

Raise and support the vehicle, then remove the front wheels. Install two standard wheel mounting nuts, diagonally opposed to each other, to secure the rotor in place. Refer to Figure 1. Attach a dial indicator with a magnetic base (2) to the inside of the rotor, then align the contact pointer (1) with the direction of the stud axis and touch the base of the outer end. Zero the dial indicator (3).

Refer to Figure 2. Grasp the outer tie rod end near the ball stud and try to move the tie rod up and down using light hand pressure (less than 10 lbs. of force). Measure and record the free play movement. If the free play exceeds 0.002”, replace the outer end. If the free play is less than 0.002”, check the inner tie rod end.

Grasp the inner tie rod end near the steering gear bellows. Try to move the tie rod up and down. If any free play is felt, replace the inner tie rod.

Note: Rotating the tie rod end is not an indication of wear.

Wheel Alignment

Now that the tires, front suspension and steering components have been inspected, checked and replaced, it’s time to realign the front end of the Chrysler 300 (LX body). First, verify that the fuel tank is full and the trunk is empty. Next, be sure the air pressure is the same in all four tires. Then, check the curb height to be sure that it is within specs.

Position the vehicle on the alignment rack and read the current alignment settings. Check the camber and caster settings first. If these settings are within specs, proceed to checking the toe. Camber and caster are set at the factory and are not normally considered adjustable angles. However, if these angles are out-of-spec (due to an accident, road damage, etc.), there are two methods that can be tried to correct these angles:

  1. Shifting the engine cradle, then
  2. Installing the adjustment bolt package (only use this package if cradle shifting does not work).

Adjusting toe on the RWD 300 is the same as any other rack and pinion-equipped vehicle. Simply loosen the jam nut on the outer end and rotate the rod to the preferred setting. Adjusting the toe on the AWD 300 is a bit different as the tie rod connection is not at the outer end housing. Refer to Figure 3. Remove the boot clamps (2) at the inner end. Loosen the jam nut (1) at the inner-to-outer tie rod connection (3) and (4), then rotate the rod to set the toe.