MODULE 3–RACK AND PINION STEERING SYSTEMS Topic A. Rack And Pinion Overview

A-3 The rack moves horizontally left or right based on the rotation of the pinion gear. A-2 Rack and pinion systems are lighter weight and require less room compared to a parallelogram steering system.

Rack and pinion steering systems:   

are lighter weight and take up less room than a parallelogram steering system. take the place of the idler arm, pitman arm, center link, and gearbox. are most common on unibody vehicles. There are some full frame vehicles, however, that use rack and pinion steering.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

On a rack and pinion steering system, the rack slides horizontally on bushings inside of a housing. The rack is moved by the pinion gear that fits into the teeth of the rack. The pinion gear is connected to the steering column shaft which is turned by driver input at the steering wheel. When the steering wheel is turned, the pinion rotation moves the rack sideways. The rack moves the inner and outer tie rods. The outer tie rod ends are connected to the steering knuckle, which moves the wheels.

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Topic B. Rack And Pinion Parts A common rack and pinion assembly contains:     

rack and pinion steering linkage. This includes the steering pinion gear and the steering rack. tie rods, both inner and outer. bushings. mounting brackets. bellows boots.

B-3 The steering rack is a long rod with teeth on one side that mesh with the pinion gear. The rack is connected to the tie rods.

The steering rack:    

is a rod with teeth on one side. meshes with grooves on the pinion gear. moves laterally based on pinion gear rotation. has tie rods on each end that connect to the steering knuckle.

B-2 The pinion gear is a grooved cylinder located at the end of the lower steering shaft that is used to move the steering rack.

The pinion gear:   

is connected to the steering shaft. has grooves that fit into teeth on the steering rack. moves the rack right or left based on the rotation of the steering shaft and pinion gear.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

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B-4 Tie rods are located between the steering rack and the steering knuckle.

Tie rods:   

connect to the end of the steering rack with an internally or externally threaded inner tie rod. connect to the steering knuckle. have a threaded end for installation onto the tie rod end.

The function and appearance is very similar to the tie rods used on a parallelogram steering system.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

B-5 Tie rod ends have a ball stud that allows lateral and vertical movement.

Tie rod ends:   

are held in place with a lock nut. have a ball stud that allows lateral and vertical movement. may have a grease zerk. TIE ROD END Select the Demonstration Icon found on screen B-5 of your CD-ROM for an example of a tie rod end.

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B-6 A bent tie rod may cause an improper toe measurement.

B-8 Ball sockets are used to connect movable steering parts.

When inspecting the tie rod ends on rack and pinion systems:

Ball sockets: 

   

look for bends in the rod. inspect for damaged or worn ball studs. inspect for damaged ball stud covers or dust covers. make sure the problem is not related to damaged tires.

If the tie rod is damaged, it must be replaced.

 

are used to connect movable steering parts. For example, ball sockets are used to connect the outer tie rod end with the steering knuckle or the inner tie rod end with the steering rack. are used at both ends of a tie rod assembly. allow a swivel motion between parts.

Typically, the moveable tie rod joint on the outside is called a ball stud while the tie rod end on the inside is called a ball socket.

REPLACING AN INNER TIE ROD Refer to screen B-7v on your CD-ROM for a video on replacing an inner tie rod.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

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B-9 A spring scale can be used to measure a ball socket for looseness.

Some vehicle makers recommend a spring scale test to measure the ball socket for looseness. To perform this test, the ball socket is rotated approximately 5 times. A specially designed tool is attached to the ball socket stud and a spring scale is attached to the tool. When the spring scale is pulled, it must measure within the vehicle maker’s specification.

B-10 Bellows boots protect the tie rod–to-rack connection from contaminants.

Bellows boots:   

are a flexible rubber covering over the inner tie rod-to-rack connection. protects the inner ball stud from dirt, dust, water, and various other contaminants. retains the lubrication at the joint.

SPRING SCALE TEST Select the Demonstration Icon found on screen B-9 of your CD-ROM for a demonstration of the spring scale test.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

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Topic C. Rack And Pinion Inspection

B-11 Torn bellows boots must be replaced.

Inspect the bellows boots for:   

cracks or tears in the boot. loose boot clamps. fluid in the boot. This is not a boot problem, however, it is an indication of a rack and pinion problem.

Boot clamps can be:   

C-1 Visually inspect the rack and pinion assembly for damage.

When inspecting the rack and pinion assembly, check:   

the ball socket wear indicator, if equipped. for worn or damaged mounting locations and bushings. for visible damage to the rack and pinion assembly or linkage parts.

self-tightened. screw-tightened. crimp-type.

The rack and pinion assembly may be:   

mounted to the front crossmember. attached to the cowl behind the engine. attached to the engine cradle.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

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Some vehicle makers recommend against servicing the power steering gear. If the gear leaks, the entire steering gear assembly should be replaced. When inspecting the position of the steering rack and tie rod ends, the vehicle must be level and the tires properly inflated. When inspecting the position of the steering rack and tie rod ends:   C-2 Check for damage to the tie-rod end seals.

When inspecting the rack and pinion assembly, check for:   

pinion shaft end-play. damaged tie-rod end seals. damage to the steering knuckles or spindles.

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make comparative measurements for consistency. measurements will not be included in the vehicle service manual. an inclinometer must be used. An inclinometer is a tool that measures the angle of a mounted part.

Hyundai Procedure For Check Free-Play With the engine running and the steering wheel in a straight ahead position, a force of 5 N (1.1lb) is applied to the steering wheel. Measure play at the circumference of the wheel. A standard value is 30 mm (1.1"). If there is excessive play, inspect the contact of the steering shaft and the tie rod ball joints. The following chart provides examples of problems, possible causes, and possible repairs to correct the problem: Condition: Rattle or clunk Possible Cause: Loose tie rod Correction: Check tie rod pivots for wear and replace if necessary

C-3 Front wheels that are not pointing straight ahead when the steering wheel is centered may indicate a bent tie rod.

When inspecting the rack and pinion assembly, check for:   

wheels not pointing straight ahead when the steering wheel is centered. steering wheel free-play exceeding 6 mm (1⁄4"). corrosion or fluid leaks on the assembly.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

Condition: Steering wheel or instrument panel vibrates during low speed or standstill maneuvers Possible Cause: Loose tie rod end jam nut or worn tie rod ends Correction: Tighten the jam nut to proper torque Condition: Steering wheel catches, sticks in certain positions, or is difficult to turn Possible Cause: Lack of lubrication in steering gear outer tie rod ends or worn ends Correction: Lubricate tie rod ends. If a lubricatedfor-life tie rod end, replace the tie rod 37

Condition: Excessive steering wheel kickback or too much steering wheel free-play Possible Cause: Loose inner tie rod or worn tie rod end Correction: Replace the tie rod

RACK AND PINION ASSEMBLY REPLACEMENT Refer to screen C-7v of your CD-ROM for a video on removing and replacing a rack and pinion assembly.

Condition: Binding, uneven turning effort, or excessive steering wheel play Possible Cause: Bent tie rod Correction: Replace the tie rod Condition: Noises or binding Possible Cause: Dry or worn ball joints Correction: Lubricate the ball joints. If a lubricatedfor-life part, replace the part

C-8 Some ball studs may be equipped with a grease zerk that allow lubricating the ball stud on a periodic basis.

When maintaining a rack and pinion assembly:   C-6 Make sure that the steering rack is mounted parallel to datum to prevent wander or pull when turning.

When replacing a rack and pinion assembly:   

damaged parts must be replaced. replacement of worn parts is necessary to restore proper steering system performance. follow the vehicle maker’s replacement recommendations.

Steering racks must be mounted parallel to datum on a vehicle. If a steering rack is not installed correctly, the vehicle may wander or pull when turning. If the steering rack is mounted parallel to datum, then both inner tie rod ends should be at nearly the same angle, within 5" side-to-side.

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

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follow the vehicle maker’s maintenance schedule. lubricate outer ball studs, if equipped with a grease zerk. use the proper steering fluid.

Note that some parts, such as outer ball studs, are lifetime sealed and do not require periodic maintenance. The following chart provides examples of problems, possible causes, and possible repairs to correct the problem: Condition: Hiss or whistle Possible Cause: Noisy valve in power steering gear Correction: Replace power steering gear Condition: Rattle or clunk Possible Cause: Internal power steering gear noise Correction: Replace power steering gear

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Condition: Rattle or clunk Possible Cause: Power steering gear loose on mounting Correction: Inspect mounting bolts and tighten if necessary to proper torque Condition: Steering wheel catches, sticks in certain positions, or is difficult to turn Possible Cause: Excessive friction in power steering gear Correction: Replace power steering gear

Topic D. Review TOPIC D. REVIEW Refer to screens D-1 through D-3 of your CD-ROM for review questions on rack and pinion steering systems.

Condition: Steering wheel catches, sticks in certain positions, or is difficult to turn Possible Cause: Bend or damage to the steering rack Correction: Replace the power steering gear Condition: Excessive steering wheel kickback or too much steering wheel free-play Possible Cause: Power steering gear loose on the cradle or crossmember Correction: Inspect and tighten bolts to specification if necessary

Steering And Suspension Program 3 v.5.1–Module 3 © 2003 Inter-Industry Conference On Auto Collision Repair

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