Steering System Diagnosis and Repair Flashcards
1
Q
What do steering column component malfunctions often contribute to?
A
Steering column component malfunctions often contribute to binding, hard steering, looseness and excessive steering wheel play.
2
Q
What should you do when experiencing excessive wander?
A
Check for steering column shaft adjustment, worn upper or lower bearings, or worn U-joint or flex coupling.
3
Q
When worn steering column bushings or bearings, leave excessive lash in the linkage, what will it cause?
A
A loose feeling in the steering wheel when driving straight, noise when hitting a bump in the road because the bushing acts as a cushion, and a pull to the left or right while driving because the wheels will drift to the pitch of the highway.
4
Q
When experiencing no steering recovery, what should you look for?
A
Look for lack of lubrication in the U-joint or flex coupling, worn upper or lower bearings, bent steering shaft or U-joints not installed properly.
5
Q
What might the cause be when experiencing excessive steering wheel movement?
A
The cause might be a loose steering wheel, worn U-joint or flex coupling, loose steering gear, a loose pitman arm, loose or worn steering linkage components, or steering gear out of adjustment.
6
Q
What should you inspect when experiencing steering column binding?
A
Inspect for worn or seized U-joint or flex couplings, steering column bearings binding or misaligned, bent steering shaft, or U-joints not properly installed.
7
Q
What should you refer to if component repair or replacement is necessary?
A
Refer to OEM procedures.
8
Q
What do most steering systems use to allow the shafts to mount on an angle?
A
Most steering systems use Universal joints (U-joints) to allow the shafts to mount on an angle.
9
Q
Describe the function of the intermediate shaft.
A
- The intermediate shaft used on most truck steering systems, runs from the lower end of the steering column shaft to the steering gear input shaft.
- The intermediate shaft connects to the steering gear input shaft with either a flex coupling or U-joint.
- In some cases, the upper end of the intermediate shaft is also equipped with a U-joint.
- With this configuration, the lower, coupler assembly can be rebuilt or is replaceable while the upper coupler assembly is not.
10
Q
What is required to prevent the possibility of speed fluctuations caused by shaft U-joints operating at an angle?
A
Proper phasing is required.
11
Q
What is the required phasing of most steering shafts during installation?
A
Most steering shafts require phasing both shaft yokes on the same plane during installation.
-This ensures that the steering gear and the steering wheel operate in unison even though the shaft speed may fluctuate.
12
Q
What should you not do when testing a linkage joint for excessive wear?
A
- When testing a linkage joint for excessive wear, you should not compress the steering column U-joint with a C-clamp or large pliers.
- This process will compress the tension spring in the joint and give the impression there is wear in the joint.
13
Q
What should you do to identify excessive wear excessive wear when testing a linkage joint?
A
Simply push against the joint with the force you can create with your hands.
14
Q
What should steering columns bearings and bushings be checked for?
A
Steering column bearings and bushings should be checked for wear, noisy operation, and binding during operation In addition, steering shaft seals and boots should be inspected for proper installation and damage.
15
Q
Since steering shaft, joint, and bearing service varies depending on the steering column type what should you do?
A
Always refer to the instructions in the manufacturer’s service manual for the proper repair/replacement procedure.
16
Q
What are the parts of cab air suspensions?
A
Cab air suspensions contain one or two air springs, two shock absorbers, and a leveling valve.
17
Q
What is the function of the leveling valve?
A
The leveling valve maintains the proper air pressure in the air springs to provide the correct cab height.
18
Q
How would you maintain the proper cab height?
A
You adjust the height control or leveling valve (similar to air suspension systems) to maintain the proper cab height.
Note: Suspension height should be set before any diagnostics are performed.
19
Q
What should a visual inspection of the air bags include?
A
Should include looking for cracking or wear of the rubber component, piston condition and mounting, dirt accumulation around the piston, and exterior components that may come in contact with the bag or interfere with bag travel.
20
Q
What should the shock absorbers be checked for?
A
Shock absorbers should be checked for proper mounting, leakage, and proper travel.
21
Q
What should the leveling valve be inspected for?
A
The leveling valve should be inspected for proper mounting, leakage, and proper ride height adjustment.
22
Q
How would you remove the steering wheel?
A
- To remove the steering wheel, begin by removing the hub cover and steering wheel retaining nut.
- Using a suitable puller, remove the steering wheel from the upper steering column shaft.
- Reinstall the steering wheel nut to prevent the steering column shaft from sliding our of the jacket tube. (if equipped).
23
Q
What precautions should you take when removing the steering wheel?
A
Do not use a knock-off type steering wheel puller or strike the end of the upper shaft with a hammer. Damage to the steering shaft bearing may occur.
24
Q
When should the steering wheel be centered?
A
When the front wheels are in the straight-ahead position.
25
What happens if the steering wheel is not centered?
* The sector shaft may not be contacting the high point of the ball nut. This condition causes erratic steering control.
* If the steering wheel is not centered, be sure the steering wheel is installed in the proper position on the steering shaft.
* after a toe adjustment, the steering wheel may require centering.
26
How would you center the steering wheel on an idler arm-type steering linkage?
The steering wheel is centered by rotating the tie rod sleeves with the proper tie rod sleeve rotating tool.
* If the steering wheel spoke is low on the left side, rotate the tie rod sleeves to shorten the left tie rod and lengthen the right tie rod.
* A one-quarter turn on the tie rod sleeves moves the steering wheel approximately 1 inch.
27
How would you center the steering on a heavy duty truck steering system?
* Centering the steering wheel on a heavy-duty steering system may be accomplished through an adjustable drag link if equipped.
* If not equipped with an adjustable drag link, ensure the front wheels are in a straight-ahead position.
* Disconnect the drag link from the pitman arm.
* Center the steering gear and check to see if the pitman arm is splined in the proper position.
* Check the measurement between the pitman arm bore and the steering control arm.
* Check the length of the fixed drag link to ensure it is the proper component.
* If correct, reinstall the drag link and then reposition the steering wheel on the steering shaft.
* Note: If a caster adjustment is required, it should be done before centering the steering system and wheel.
28
What are the the six conditions that the steering angle sensor must be re-calibrated as part of?
1. Steering wheel replacement.
2. Steering angle sensor replacement.
3. Any maintenance that involves opening the connector hub from the steering angle sensor to the column.
4. Any maintenance or repair work on the steering linkage, steering gear, or other related mechanism.
5. Wheel alignment or wheel track adjustment.
6. Accident repairs where damage to the steering angle sensor or assembly or any part of the steering system may have occurred.
29
What cautions should you take when replacing a steering wheel?
Use only OEM-approved steering wheels. Take care not to damage the steering angle sensor or interfere with its operation during installation.
30
Before inspecting steering components, what are the steps you should take?
>If possible, interview the driver to determine if the issue is ongoing or only occurs under certain conditions.
>Road test the vehicle under the conditions described and try to duplicate the condition.
>Pay particular attention to speed, load factors, directional issues, and noisy operation.
>Tire inflation and suspension component condition may also play a role in steering system issues.
31
What can be the cause of power steering system "noise"?
Noise can be caused by various sources. A visual and audible inspection must first be performed to determine cause. (check belts, fluid level, mounts, etc)
32
What can be the cause of power steering system binding, and turning effort, Hard steering?
This can be the result of improper torque applied to any newly installed components; seized or under-lubricated moving components; improper phasing during the installation of shafts and/or U-joints; loose drive belts; misalignment due to wear. fatigue, or collision damage; or improper servicing of power steering filters.
33
What can be the cause of power steering system looseness?
Improper torque specifications (i.e. steering box pre-load) and worn improperly installed components can lead to excessive steering wheel movement.
34
What can be the cause of power steering system darting/oversteer?
Loose steering components and/or a misadjusted power steering gear may cause this condition. Tire inflation, load factors, and suspension component condition should also be inspected.
35
What can be the cause of power steering system reduced wheel cut?
May be caused by misadjusted power steering gears, wheel stops not being adjusted properly, or bent mechanical steering components.
36
What can be the cause of power steering system Wheel kick?
May be caused by air in the hydraulic system, loose steering gear mounting worn stereing linkage, front wheel bearings not adjusted or worn, improper steering gear adjustment, damaged or worn steering gear components, or worn or missing poppet valves.
37
What can be the cause of power steering system pulling and non-recovery?
May be a result of a variety of mechanical and/or hydraulic issues. In addition, front-end alignment, tire inflation, load factors, and road conditions may also have an effect on the steering components.
When determining the cause of pulling and non-recovery complaints, check tire pressures, wheel bearing adjustments, suspension components, and ride height adjustments in addition to inspecting steering system operation and components. If no mechanical or hydraulic issues are found, perform a front and rear axle alignment factors may be contributing to the issue.
38
What can be the cause of power steering system fluid leakage and aeration?
Inspect for visual signs of external and internal fluid loss. Correct as necessary.
An overfilled reservoir may be the result of a restricted high-pressure line.
An air leak on the low-pressure side would lead to air being ingested into the hydraulic system, which would lead to both overfill and foaming (aeration).
39
What will cause the steering wheel to become more off center over the course of 500 miles?
A loose sleeve clamp on the drag link adjuster with damaged adjusting threads.
40
What will cause steering wheel freeplay?
A worn steering shaft U-joint or an out-of-adjustment steering gear.
41
What will cause a wheel and tire not to return to the straight-ahead position during a front axle and linkage-binding test?
Defective kingpins or kingpin bearings.
42
What will cause high steering effort and fast steering wheel return?
Excessive positive caster.
43
What can be possible leak sources of fluid leakage?
Reservoir o-rings, driveshaft seals, high-pressure fittings and the dipstick cap.
>If leaks occur at any of the seal locations, replace the seal.
>When a leak is present at the high-pressure fitting, first tighten it to the specified torque. It this fails, replace the o-ring at this fitting.
44
Some original equipment manufactures recommend the use of power steering fluid or automatic transmission fluid in power steering system. Others recommend engine oil. Care must be taken to use the correct oil. What will low fluid level cause?
Low fluid level will cause increased steering effort and erratic steering.
It may also cause a growling or cavitation noise in the pump.
45
What will foaming in the remote reservoir indicate.
Foaming in the remote reservoir may indicate air in the power steering system.
46
What temperature do most OEM truck manufacturers recommend?
Most OEM truck manufacturers recommend checking the power steering fluid level at operating or working temperature of 140-160 degrees F.
47
How would you raise the fluid temperature?
With the engine at 1,000 rpm or less turn the steering wheel slowly and completely in each direction several times to raise temperature.
Check the reservoir for foaming as a sign of aerated fluid.
The fluid level in the reservoir should be at the hor-full mark on the dipstick.
48
What is it important to do before servicing the power steering system?
It is important to identify the manufacturer and to identify if the steering gear is a standard or inverted mount.
49
What is the procedure for flushing and refilling power steering system and purging air from system?
When you drain and flush the power steering system, disconnect the return hose from the remote reservoir to drain the fluid.
When the fluid begins to discharge from the return hose, shut off the engine.
After the power steering system has been drained and refilled, the steering wheel should be turned fully in both directions with the engine running to bleed air from the system.
Note: Front wheels should be raised off the ground; this will reduce heat on fluid and aid in purging air from system.
50
What are the procedures for testing power steering system pressure?
~ The steering analyzer should be connected from the power steering pump high-pressure hose to the steering gear.
~The load (gate) valve should be open at the beginning of the power steering pump pressure and flow text. Start the engine, run at idle speed, and observe the pressure and flow on the analyzer.
~If the power steering pump flow is less than the OEM specified pressure (usually 200 psi), check the high-pressure hose for restrictions. If the pressure is above the OEM specified pressure 200 psi at idle with the load valve open, check the return line for restrictions. If the flow rate is less than the OEM specification 2 gpm (gallons per minute), the pump or the flow control may be defective.
~Rotate the gate (load) valve toward a closed position until the pump pressure rises to 700 psi and increases to the test value specified in the OEM service literature. This may be between 500 and over, 1,000 psi depending on the system. If the flow rate is 1 gpm (gallons per minute) less than the flow rate recorded with the gate (load) valve open the pump or flow control valve is bad.
~Ensure that after the analyzer is removed, the engine is run, and the steering gear is turned from lock to lock and then back to center before driving the vehicle. This will ensure that no air remains in the high-pressure circuit.
51
Power steering systems may have either an integral or remote fluid reservoir. What can be the source of leaking power steering fluid?
Can be the lower-sector shaft seal, submersed-style pump-to-reservoir surface, or supply-line double-flare fitting.
52
What may prying on the reservoir to adjust the pump drive belt do?
May damage or puncture the reservoir.
53
What steps should you use to remove the remote reservoir?
~ Stop the engine, remove the cover, and using a suction gun, remove the fluid from the reservoir.
~ Use the appropriate stops to drain fluid out of the hoses and remove the reservoir.
~ Remove the spring, filter cap, and filter from the bottom of the reservoir.
~ Install a new filter, filter cap and spring.
~ Install the reservoir and torque to specifications.
~ Fill and bleed the system.
54
What can loose belt tension cause?
Loose belt tension can cause the lack of power assist in the steering system.
55
What kind of inspection would you use to determine if the belt or pulley is worn to and extent that replacement of either unit is needed?
Perform a visual inspection.
56
What does a glazed (polished, shined) belt indicate?
Indicates that a few items must be in inspected.
57
How should belt tension checks be performed?
Should be performed using a belt tension gauge and checked midpoint between the pulleys at the longest belt span.
~ Is the belt the proper length and width?
If these are within specification, check the pulley for excessive wear. This can be determined by measuring the depth of a new correct belt as it sits in the pulley.
~ Does it bottom out in the groove?
If so, then the pulley is worn and must be replaced.
~ Is the pulley damaged or loose on the shaft? Is alignment correct?
This is not so critical on V-belt installations but is a constant cause of bearing failure in serpentine belt applications, as there is considerably more belt wrap and surface area involved and more side loading effect on the bearings (Most of which are ball type versus tapered roller), which leads to premature failure.
58
What do Manufacturers such as Caterpillar specify when performing all adjustments?
Caterpillar specifies the use of a laser alignment tool to perform all adjustments and have 1 degree as the ideal maximum out-of-tolerance specification between pulleys.
59
What is the power steering pump used to produce?
Is used to produce the hydraulic circuit flow required for the power steering system.
They may be belt or gear driven depending on the vehicle application.
60
What should you consider when inspecting the power steering pump?
Consideration should be given to the pump mounting bolts to ensure that the correct torque is applied and mounting brackets checked for signs of movement, cracking, or distortion.
If the pump is belt driven, the belt condition and tension should be checked.
Also the belt pulley should be inspected for wear, damage, and proper alignment.
61
If there is a lack of hydraulic pressure, what is necessary to test/
It is necessary to test the system's pump if there is a lack of hydraulic pressure.
Low pressure can be caused either by pump problems or by problems in the steering gear.
62
What do pump tests tell?
Tells the technician which part is causing the problem.
63
What would a complete test of the system's pump require?
A complete test of the system's pump requires testing for both pressure and volume. Flow and pressure meters are installed on the complete system.
64
What does a whining noise usually heard coming from the pump a cause of?
When the power steering pump lacks the ability to perform its primary function properly, is low on fluid, or when air is introduced into the system.
65
If the pressure is low and the flow is low, what is probably the problem?
The pump is probably the faulty component.
66
What is causing the problem if the pressure is low but the flow is normal?
Chances are that excessive internal clearance in the steering gear, due to wear.
67
What should the inspection process of the power steering pump, drive gears/shafts, mounting, and brackets also include?
Should also include looking for external leakage. Sources for oil leakage are the drive shaft seal, reservoir o-ring seal, high-pressure outlet fitting, and the dipstick cap.
Inspect the hose condition for cracking, brittleness, leakage, or chafing due to external components rubbing against the hose.
Check to see if there is an adequate amount of the correct type of fluid, noting any discoloration. Air in the system will cause the fluid to have a foamy appearance.
If the pump is overheated, the fluid will become dark.
If the fluid does become discolored, other problems may exist in the power steering system.
68
What must you do if internal damage is suspected due to low fluid levels or overheating?
The power steering pump must be removed and disassembled to determine the extent of the damage.
69
How can you identify a damaged power steering pump?
A damaged power steering pump can be identified by score marks in the pump drive gear.
Elongated mounting holes in the power steering pump bracket may cause a noise while in operation.
70
What could cause premature belt wear?
Worn holes in the power steering pump mounting bracket could cause premature belt wear.
71
What are the do's and don'ts of replacing the power steering pump drive on a truck with a diesel engine?
It is not necessary to re-time the engine when this replacement process is complete.
Inspect the driven gear for worn or chipped teeth.
Perform these tasks when removing and installing a gear-driven power steering pump:
Check pump mounting holes for wear,
remove hoses from pump and cap the fittings,
replace the o-ring,
and bleed the air from the power steering system.
72
How does power steering fluid under pressure from the pump via the high-pressure hose flow?
Flows through the steering gear and continues through a low-pressure hose to the cooler and pump reservoir.
73
What should you do when you inspect and replace power steering cooler, lines, hoses, clamps/mountings, and fittings?
You should check the power steering cooler air passages and fins for restrictions during any preventive maintenance process.
You should check all power steering hoses for leaks, cracks, dents, and sharp bends.
You should also torque all pressure fittings to specifications before replacing the o-ring.
74
What does linkage assist-type power steering systems incorporate?
A torque valve mounted in the drag link, a power cylinder attached to the front axle assembly and tie rod cross tube, a safety valve located in the air line from the brake reservoir and the torque valve, and a manual steering gear.
75
What will worn kingpins, improper steering-gear mesh prelude, or a bent worm gear cause?
Will cause a linkage-assist-type power steering to bind when turning corners, but with short steering corrections, wheel recovery is normal.
76
What can low lubricant level in the steering gear cause?
Can cause the manual steering gear assembly of a linkage-assist-type power steering to become noisy when turning the steering Wheel.
The mechanical components should be inspected for proper operation, adjustment, and wear whenever a steering complaint is registered.
77
How would you inspect, adjust, or replace linkage-assist-type power steering cylinder or gear (dual system)?
- Inspection of linkage-assist-type power steering system should start with an inspection of the air system reservoir.
- Drain the air tank to ensure no water or contamination is found.
- Inspect all air lines and fittings for chafing, proper routing, and leakage.
- Inspect the safety valve, the torque valve, and the power assist cylinder for proper operation, leakage, and damage.
- Every 25,000 miles or three months, the system should be lubricated internally.
- If any components are found to be in need of adjustment or are defective, refer to the manufacturer's service material for the proper procedures.
78
What is a good starting point in troubleshooting a power steering gear?
A good starting point is checking the performance of the system in terms of both operating smoothness and steering wheel play.
79
How would you begin checking the steering gear?
- Begin checking the steering gear by feeling for and measuring the steering wheel free play with the engine running and the truck at a standstill.
- After determining excessive play, have an assistant turn the wheel slowly back and forth as you observe the operation of the linkages (engine on).
- Inspect all external steering linkage and the U-joint at the base of the steering column first for looseness.
80
What may happen if any part of the system is binding?
If any part of the system is binding, the linkage may cause difficult steering and make the driver suspect power steering hydraulic problems when the trouble is a simple, mechanical part of the steering system.
- If the binding seems to occur in the steering gear itself, it could be due to a worn or damaged bearing.
- If the gear is an adjustment for the sector shaft, adjust it to specification.
81
What should you do to measure steering gear pre-load torque and why?
Both the input and output shafts should be disconnected.
- This process prevents binding in the steering column or linkage from affecting the worm bearing preload and sector lash adjustments.
82
How would you center the steering?
Turn the worm shaft from stop to stop and count the number of turns.
- Starting at one end of the worm shaft travel, turn the worm shaft back half the number of turns from stop to stop.
- This action centers the steering gear in preparation for the sector lash adjustment.
83
How would you perform a steering gear internal leakage test?
- The first step is to prevent oparation of the gear's internal unloading valves.
- These may be a simple pressure relief valve or a valve located at either end of the steering gear piston's travel.
84
How would you read pressure and flow?
Have an assistant turn the steering wheel until the steering gear contacts the axle stops.
- Have him or her hold it there for just a few seconds while reading pressure and flow.
- The pressure should be at the pump relief pressure. Flow should be compared to factory specifications for gear leakage.
- If steering gear leakage is above acceptable levels, the steering gear should be overhauled or replaced.
85
What happens when the front wheels are turned in a power steering gear?
Torsion bar deflection moves the spool valve inside the rotary valve.
- This valve movement directs power steering fluid to the appropriate side of the worm shaft piston to provide steering assist.
86
In many steering gears, what is the function of a poppet or relief valve located either in the piston or housing?
Allows for an automatic reduction of assist pressure when the road wheels come close to, or reach, their turning limits.
- A piston travel approaches the steering limit, an adjustable plunger will contact and push the valve off its seat.
- The valve, when unseated, allows for some of the assist pressure to flow back to the fluid return side of the steering gear.
- This partial exhausting of pressurized fluid allows for a reduction in system temperature and pressure, relieving stress on the mechanical components of the steering system.
87
What should you do if the steering gear poppet/relief valves are found to be in need of adjustment?
A poppet valve service kit must be installed. Consult the manufacturer's repair manual to insure the correct procedure is being followed to install the service kit and adjust the poppet valve.
88
What can the pitman be responsibility for?
Can be directly responsible for directional stability.
89
What can a damaged pitman arm be directly responsible for?
Can be directly responsible for the steering wheel being off center.
90
What could a loose pitman arm on the steering gear output shaft?
Could cause a steering shimmy below 30 mph.
91
What should you do it removal or replacement of the pitman arm is required?
- Scribe mark the pitman arm in relation to the steering gear output shaft and use a suitable puller to remove.
- Upon installation, align the scribe marks made upon removal.
- When you replace a steering or pitman arm, you should perform all of the following: road test when repairs are completed, check and correct for changes in wheel alignment, and lube the the replacement part after installation.
92
What is the drag link?
It connects the pitman arm to the steering control arm.
It can be either a one-piece or two-piece design.The length of the two-piece design is adjustable, which makes it easy to center the steering wheel.
93
What will a loose sleeve clamp on the two-piece drag link do?
May allow enough play in the sleeve to damage the adjusting threads, and this action may change the steering wheel position.
94
What could a mis-adjusted drag link cause?
Could cause the steering gear to operate off center and can cause a steering wheel shimmy.
95
Ho would you adjust the drag link or set the toe adjustment?
Before you adjust the drag link or set the toe adjustment, check ball joint motion in each end of the drag link and/or tie rod.
- Use hand pressure only to check ball sockets for excessive wear and movement.
96
What may a worn relay rod socket or an out-of-adjustment tie rod cause?
May cause a wandering condition while driving.
- Also check the rubber boot for damage.
- Be sure to thread the tie rod end in beyond the split or damage to the relay rod may occur.
97
What can a damaged or bent steering arm cause?
Can cause a change in the steering wheel position and affect Ackerman geometry, turning radius, toe-out on turns, and tire wear.
98
What can a damaged or bent upper steering arm in the driver's side steering knuckle cause?
Can cause a change in the steering wheel position.
99
What should inspection of the steering arms include?
Should include inspection of the tie rod end mounting for looseness.
- If looseness is found, the tie rod end should be removed and the tapered bore checked for damage.
- Torque the castellated nut and install a new cotter key.
100
How would you test a steering linkage joint for excessive wear?
You should simply push against the joint with force that you can create with your hands. This should be enough to identify excessive wear.
101
What does the type of spindle arrangement determine?
The upper and lower steering arms may or may not be able to be replaced separate from the spindle assembly.
- If the upper and lower arms are replaceable, ensure that the new component matches the old component.
- Remove the tie rod end ball sockets using the proper tool to prevent damaging the ball socket.
- Once the steering arm has been replaced and the ball sockets reinstalled, torque all retaining nuts and bolts to manufacturer's specifications and be sure all cotter keys are installed and secure.
102
How would you inspect and replace tie rod cross tube clamps, and retainers.
- The length of the tie rod determines the front wheel toe.
- Inspection of the cross tube should include the tie rod end ball sockets for wear, tie rod end grease boots for damage.
- A tie rod clamp that interferes with the I-beam on a full turn will cause a noise when turning over bumps.
- Tie rod clamps are installed with the clamping bolt opposite the split in the tie rod cross tube.
- When replacing the tie rod ends, the technician must insert the threaded portion of both tie rod ends into the cross tube until they are threaded in beyond the split at each end of the cross tube.
103
`What happens if the wheel stops are missing, damaged, or out of specified adjustments range?
They can cause excessive turning radius and damage to tires, hoses, and body panels.
- The wheel-stop bolts to produce the correct turning radius.
