1.83k likes | 4.51k Views
Steering Systems. Chapter 44. Contents. Steering system problem diagnosis Steering system maintenance Steering column service Manual steering gearbox service (recirculating-ball type) Steering linkage service Manual rack-and-pinion service Power steering system service. Steering System
E N D
Steering Systems Chapter 44
Contents • Steering system problem diagnosis • Steering system maintenance • Steering column service • Manual steering gearbox service (recirculating-ball type) • Steering linkage service • Manual rack-and-pinion service • Power steering system service
Steering System Problem Diagnosis • Symptoms of steering problems include play in the steering wheel, hard steering, and abnormal noises when turning • Inspect and test the steering system to find the source of the trouble
Steering Wheel Play • Amount that you can turn the steering wheel without front wheel movement • Caused by worn ball sockets, a worn idler arm, or too much clearance in the steering gearbox • Compare the play to service manual specifications • e.g. 1 1/2” (33 mm)
Dry Park Test With the vehicle on the ground, rotate the steering wheel back and forth while someone watches for part wear
Steering Inspection Raise the vehicle on a lift. Wiggle thetires back and forth while watchingfor steering play
Hard Steering • Caused by problems with the steering gear, power steering components, ball sockets, and the suspension system • Check the power steering pump belt for condition and tension • If the belt is slipping, hard steering could result • Check for cracks and glazing and compare tension to specs
Steering System Noise • Noise can be a sign of worn parts, dry bearings or ball sockets, loose parts, slipping belts, or low power steering fluid level • Belt squeal and power steering pump noise both occur when the steering wheel is turned • Pump noise can result from low fluid level or aerated fluid
Steering System Maintenance • Maintenance involves checking for low fluid level, incorrect belt adjustment, system leaks, and other problems • Ball socket lubrication may be necessary
Checking the Fluid Check most systems at operating temperature, with the engine off
Servicing the Belt When changing a belt, pry on a recommended point and adjusttension to specs
Steering Column Service • Service is needed after a collision or when internal parts of the column fail • Most repairs can be done without column removal
Steering Wheel Removal • Remove the horn button and steering shaft nut • Scribe alignment marks on the steering wheel and the steering shaft • Mount a wheel puller over the steering wheel • Screw the bolts into the threaded holes in the steering wheel
Steering Wheel Removal Tighten the puller down against the steering shaft to remove the wheel
Steering Wheel Installation • When installing the steering wheel, match any alignment marks • Many steering shafts use a master spline so that the wheel only installs in one position • Ignition lock, turn signal mechanism, and horn and cruise control slip rings are all accessible below the steering wheel
Manual Steering Gearbox Service (Recirculating-Ball Type) • Service involves the adjustment or the replacement of worn parts (bearings, seals, and bushings) • Gearbox repair or overhaul may be necessary when adjustment will not provide proper operation
Gearbox Adjustment • Two basic adjustments are performed on manual recirculating-ball gearboxes: • Worm bearing preload • preloads the bearings to ensure that the worm shaft is held snugly in the housing • Over-center clearance • controls the amount of lash between the pitman shaft gear and the teeth on the ball nut
Worm Bearing Preload Adjustment • Disconnect the pitman arm • Loosen the pitman shaft over-center locknut and adjusting screw • Using a torque wrench or spring scale, turn the steering wheel slowly from side-to-side
Worm Bearing Preload Adjustment Compare the required force to specs If needed, tighten or loosen the adjustment nut
Over-Center Clearance Adjustment • Center the steering gear in its travel • Preload is produced in the center of travel to avoid steering wheel play during straight-ahead driving
Over-Center Clearance Adjustment Loosen the locknut and bottom the adjustment screw lightly
Over-Center Clearance Adjustment • Use a torque wrench or spring scale to measure the amount of force needed to move the shaft back and forth through center • Tighten or loosen the adjusting screw until the amount of force needed to move the shaft is within specs • Tighten the locknut after adjustment and recheck the required force
Steering Linkage Service When your inspection finds worn steering linkage parts, new parts must be installed
Idler Arm Service • Idler arm wear will cause play in the steering wheel • To check an idler arm, force it up and down using a spring scale • When the specified force is applied to the spring scale each way, note the idler arm movement and compare to specs • e.g. at 20 lbs (9.0 kg) of force, maximum 1/4” (6.5 mm) travel
Idler Arm Service • To replace the idler arm, remove the cotter pin and castle nut • Use a fork tool or puller to force the ball stud out of the hole in the center link • Unbolt the idler arm from the frame • Install the new part • Torque the idler arm to specifications • Install a new cotter pin
Tie-Rod End Service • Tie-rod end wear will cause steering play • To remove a tie-rod end, separate the tie-rod end from the steering knuckle or center link
Tie-Rod End Service Use a fork or puller to separate the tie-rod end from the steering knuckle
Tie-Rod End Service Loosen the adjusting sleeve, and count the number of turns required to remove the tie-rod from the sleeve
Tie-Rod End Service • Install the new part the exact same number of turns • Install the tie-rod ball stud into the center link or steering knuckle • Tighten all of the fasteners to specs and install a new cotter pin • Check toe adjustment with an alignment machine
Power Steering System Service • Service involves the adjustment or the replacement of worn bearings, seals, and bushings • Hoses, a pump, a power piston, and a control valve are added • these parts can require repair or replacement
Power Steering Leaks • To check for leaks, wipe fluid-soaked areas clean • Have a helper idle the engine and turn the steering wheel to the right and left • Watch for leaks as the wheels are turned, raising system pressure
Servicing Hoses • Always check hose condition when servicing a power steering system • High-pressure hoses are exposed to tremendous pressures • over 1000 psi (6895 kPa) • When installing a new hose, start fittings by hand • Use a tubing wrench to tighten the hose fittings properly
Pump Replacement Bolts, hoses, and brackets that must be removed when replacing a pump
Pump Service • During a pump rebuild, clean and inspect all the parts • Check the pump vanes, thrust plate, and pump ring (included in a pump rebuild kit) • Replace all o-rings, gaskets, and seals • Lubricate the components with fluid and reassemble the pump
Bleeding the System • When hydraulic components are serviced, bleed any air out of the system • Idle the engine and turn the steering wheel fully from side to side • Check the fluid level often • Cycling the system will force air from the steering gear, back to the reservoir
Electronic Assist Steering Service • Refer to service manual diagrams, part locations, and electrical value charts • Use a scan tool to check for diagnostic trouble codes • Check scan data for input and output data that could help isolate a problem • Perform pinpoint tests with a multimeter to verify the source of any problems