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Steering Repair tips
After you locate the damage on a steering system, your greatest challenge will be determining the correct repair. Review the list of problems to look for during a test drive. Note how one problem can have numerous causes or numerous combinations of causes. When performing repairs, your primary goal is to be thorough. Make all the necessary repairs, and make sure you are solving the source of a problem, not just one of the symptoms.
For example, consider what can happen when a vehicle with recirculating ball steering and parallelogram linkage is wrecked. During an accident when the driver has turned the wheels fully in one direction (usually to avoid the collision), a curb or other object can strike the wheels in that same direction. This can twist the sector shaft and prevent the steering wheel from returning to a centered position.
In some of these cases, a technician will notice the off center wheel and repair it by performing a wheel alignment. While the wheel remains centered, the real problem remains; the sector shaft is twisted and weakened. It may break and disable the steering at a critical time when the vehicle is being driven.
To avoid making this mistake, always look at the splines where the shaft comes out of the steering box. The splines should be straight. If not, the sector shaft probably is bent. Another indication of a bent sector shaft is the steering being off center while the vehicle is driven straight and the toe is correctly adjusted. This also assumes there is not a rear thrust angle problem.
A twisted sector shaft must be replaced, either by replacing the sector shaft alone or by replacing the gear box with a rebuilt, new or salvaged unit. If you do need to replace the sector shaft, be aware that some vehicle makers refer to it as a Pitman shaft.
Following are some repair tips:
- Always replace damaged dust boots on tie-rod ends and rubber bellows or boots where the tie rods enter the rack. A damaged boot or bellow will allow dirt in and cause premature failure of the ball socket.
- When an inner tie-rod is replaced, make sure the rack is properly supported. Always ask another technician for help. The bellows on both sides typically need to be loosened to allow access to the rack itself. If the rack is not held stable while the bellows are loosened, it can be damaged.
- If the toe needs to be aligned and a wheel has been damaged in a collision, always check for a damaged steering arm on the knuckle. This is another problem that is frequently misdiagnosed and repaired by adjusting the tie rod end. If the steering arm remains bent and the toe is reset, the toe adjustment will be off and will create problems with the Ackerman steering or turning radius. During a turn, the inside wheel is designed to turn at a greater angle than the outside wheel. This is because the circle that the inside wheel turns on is smaller than the outside wheel. If the steering arms are bent, the change in geometry produces a turning radius different from the radius the vehicle was designed for. This can cause scrubbing of the tires as a corner is negotiated. Prevent this problem by checking the steering arms for signs of damage, such as flaking coatings or rust on the knuckle where the steering arm protrudes. You can also use a straight edge to measure from the steering arm to the tie-rod end. Compare the measurement to a measurement taken on the opposite side of the vehicle.
- When it comes to bent pieces in the airbag system, never repair and always replace. The system is extremely sensitive to the slightest changes, and you don't want to take any chances.
- Steering linkage parts are manufactured from malleable materials and are designed to bend or deflect rather than fracture under extreme stress loads. This toughness and malleability are necessary to avoid the complete loss of control that would occur if any part of a steering linkage were to break. Steering linkage parts therefore must never be
heated during a repair because it could cause them to lose their malleability and fracture.
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