Servicing Suspension System

SELF CHECK LO1-8a

1. Describe briefly how the car should be lifted to check each of these ball joint.
A. _____________________________________
B. _____________________________________
C. _____________________________________
D. _____________________________________
E. _____________________________________
F. _____________________________________

2. What is the technician doing?

How will he know if it is good?

3. What does this dimension mean?

How do you check the ball joint using it?

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 47

4. What is this technician doing?
How can he isolate areas that are being checked?

5. How would you check the circled item?
What is it?

6. What is this technician doing?
List the parts that can affect it.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 48

ANSWER KEY LO1-8a

1. A, B, and F: Lift by frame with prop under upper arm, C, D, and E: Lift under lower control
arm.

2. He is checking a wear indicator ball joint. If he can’t rotate the perk fitting, the ball joint is
worn.

3. If this dimension changes more than 3/32” when the ball joint is unladed, the ball joint is bad.

4. He is checking for play at the wheel bearings, ball joints, king pin, and control arm bushings

5. Measure the distance it moves as the vehicle is lifted or measure the amount of side motion
as the spring is pushed and pulled

6. He is checking for play in the steering linkage, wheel bearings, tie rod ends, idler arm,
Pitman arm end, steering gear, steering couplers.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 49

INFORMATION SHEET LO1-9

Figure LO1-9a. Hydraulic floor jack and Fig. LO1-9c. Jack stands are used under to support the
engine support tool vehicle.

REAR LIFT POINTS FOR SINGLE
POST LIFT

Figure LO1-9b. Designated lift points for one vehicle, specified by the vehicle manufacturer

The automotive shops use a variety of hydraulic jacks. One type is the portable floor jack
(Fig.LO1-9a.). Pumping the handle increases the pressure in the hydraulic cylinder. This causes
the ram to extend and raise the lifting saddle. Turning the top of the handle or moving a lever on
the handle releases the pressure. Then the saddle and load settle back down.

Always lift at the proper lift point under the vehicle (Fig. LO1-9b). If in doubt, refer
to the vehicle manufacturer’s service manual. Lifting at the wrong points can cause
vehicle damage.

CAUTION!

Never work under a vehicle supported only by a jack. Always support the vehicle on safety
stands before going under it (Fig. LO1-9c) A jack could slip or release. Then the vehicle would
fall on you. Serious injury or death could result.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 50

INFORMATION SHEET LO1-10

SHOP SAFETY RULES

6. Make sure your clothes are right for the
job. Dangling sleeves or ties can get
caught in machinery and cause serious
injury. Do not wear sandals or open-toe
shoes. Wear full leather shoes with
nonskid rubber heels and soles. Keep long
hair out of machinery by wearing a cap.

Figure LO1-10a. 7. Do not wear any rings, bracelets, or
watches when working moving machinery
or electrical equipment. Jewelry can catch
in moving machinery with very serious
results. Also a ring or bracelet can
accidentally create a short circuit of the
battery. Then the metal of the ring or
bracelet may become white hot in an
instant. This will severely burn you.

Some people say, “accidents will 8. Wipe oil and grease off your hands and
happen!” But safety experts disagree. They tools. You need a good grip on tools and
say “Accidents are caused.” They are caused parts.
by careless actions. They are caused by
inattention to the job. And they are caused by 9. If you spill oil, grease, or any liquid on the
using damaged or incorrect tools.” Fewer floor, clean it up. Help prevent injury from
accidents occur in shops that are neat and slips and falls.
clean.

To help prevent accidents, follow these safety 10. Never use compressed air to blow dirt from

rules. your clothes. Never point a compressed air

blowgun at another person.

1. Work quietly and give your full attention 11. Always wear eye protection when liquid
to the job you are doing. spray or particles are flying about. Safety
glasses, safety goggles or face shield (Fig
2. Keep your tools and equipment under LO1-10b) should always be available.
control Always wear eye protection when using
grinding wheel (Fig. LO1-10c).
3. Keep jack handles out of the way (Fig.
LO1-10a). Stand the creeper against
the wall when not in use.

4. Never indulge in horseplay or other
foolish action. You could cause
someone to get seriously hurt.

5. Never put screwdrivers or other sharp
objects in your pocket. You could cut or
stab yourself. Or you could damage the
upholstery in a car

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 51

Fig. LO1-10b. Always wear safety glasses, safety Figure LO1-10c. Always wear eye protection when
goggles, or a face shield when liquid spray or using a grinding wheel.
particles are flying or falling around you.

12. Watch out for sparks from a grinding
wheel or a welding job. The sparks can
set hair or clothes on fire

13. When using solvents or other chemicals, Figure LO1-10d. If solvent or some other chemical
wear goggles to protect your eyes. If you splashes in your eyes, immediately wash them out
get a chemical in your eyes, flush them
with water at once (Fig. LO1-10d) then go with water.
to the school nurse.

14. Always use the right tool for the job.

15. Keep your hands away from the engine fan and accessory drive belts when the engine is
running. Your hand could get caught in the fan r between a belt and a pulley. You could be
badly cut or even lose a fingers.

16. Do not stand directly in line with the engine fan when it is turning or the engine is running.
Some fans, especially fans with flexible blades, have thrown off a blade while spinning. A
flying fan blade may injure or kill anyone it strikes.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 52

JOB SHEET LO1-1

INSPECT SUSPENSION SYSTEM

The purpose of an inspection is to
determine the cause for the vehicle owner’s
complaint and to determine what steps will be
needed to cure the complaint. It is a god
practice to note any other parts that show
signs of failing in he near future so the
customer ca be aware of them. The
suspension should operate for many miles and
a year or so until the next time it is inspected;
the average motorist does not check
suspension components very frequently
(Figure LO1.1a).

Figure LO1-1a. As the suspension parts wear, they
allow the alignment of the front tires to chance and
permit uncontrolled, sloppy tire movement.

SAFETY TIP: A suspension, steering, or brake failure can place the car and its passengers in a
highly dangerous situation. While making an inspection, this fact is in the forefront of the front-
technician’s mind. Any item that might fail in the near future and cause an accident is noted and
brought to the car owner’s attention.

Sometimes an inspection will determine that a simple adjustment or realignment is all
that is needed to correct the situation; often a worn bushing or ball joint will show up. Worn
parts must be replaced before an alignment can be done. It does no good to do a wheel
alignment if the suspension parts are sloppy. In most cases on an older car, when realignment
is necessary, that need is probably caused by worn parts or sagged springs. Remember tat the
rear wheels also have a suspension system and that their parts also wear out. Rear suspension
bushings and pivots are checked in the same manner as those at the front.

As an inspection is being performed, it is a good practice to follow a set procedure to
ensure that portions of the suspension and steering systems are not skipped or forgotten. When
checking a modern car, another good practice is to note the instrument panel lights as you start
the engine. They will indicate if the car has ABS or an airbag and if these systems are operating
properly.

A suspension and steering system inspection should include checks of the:

1. Steering wheel for excessive steering looseness or binding.
2. Tires for correct inflation.
3. Tires for wear pattern to give an indication of incorrect alignment, balance, or worn parts,

and also for physical defects that might cause failure.
4. Vehicle for correct height and attitude.
5. Vehicle for optional springs, shock absorbers, or overload devices that might change the

ride quality or alignment.
6. Tire spinning (by hand) for tire runout and wheel bearing condition.
7. Tire and wheel shake (top and bottom) for wheel bearing looseness.
8. Tire and wheel shake (side to side) for steering component looseness.
9. Ball joints for excessive looseness, boot condition, and binding.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 53

10. Control arm bushings and end links for wear or deterioration.
11. Strut rod bushings for wear deterioration.
12. Stabilizer bar bushings and end links for wear or deterioration.
13. Springs for loose or broken parts.
14. Shock absorbers or strut for leakage, loose or broken mounts or broken parts.
15. Tie rods for looseness or torn boots.

Many technicians follow an inspection checklist (Fig LO1-1b). The checklist helps ensure
that none of the checks is missed or forgotten, and it allows a more professional discussion with
the car owner.

™ Spring and shock absorber Inspection

An inspection of the springs and the shock absorbers often begins with a customer
complaint of noise, tire wear low vehicle (one end, one side or all over, excessive vehicle
leaning on turns, or front end dive under braking. Any of these complaints might indicate
weak or broken springs or shock absorbers.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 54

Figure LO1-1b. Many technicians follow a checklist like this to ensure that they do not skip any checks and also to
give the car owner a record of what was found during the inspection.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 55

ASSESSMENT TASK LO1-1

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 56

OPERATION SHEET LO1-1

OPERATION TITLE : PERFORM BOUNCE TEST

PURPOSE :

The bounce test is a simple and quick test that should give an indication of the condition
of the suspension system.

EQUIPMENT TOOLS AND MATERIALS:

• Vehicle equipped with suspension system

PROCEDURE:

1. Grip one end of the bumper and alternately Figure 1. A shock absorber bounce test is manually
pull upward and push downward several performed by bouncing each corner of the car; with the
times until you get that corner of the car car bouncing as much as possible, it is released and the
bouncing up and down as high as you can.
While the car is bouncing up and down, bouncing action is observed. If it bounces more than
listen for any unusual noises that might one and half oscillations, the shock absorber is probably
indicate worn or broken parts.
weak.
2. With the car at the upper end of a bounce,
release the bumper and watch the
remaining oscillations until they stop. Two
or more oscillations indicate the possibility
of worn shock absorbers or, less likely
worn front-end bushings (Fig 1).

3. Repeat steps 1 & 2 at the other end of the
bumper and compare the bouncing action
of the two sides of the car. They should be
the same; a difference indicates a weak
shock absorber or worn suspension
bushings.

4. Repeat steps 1, 2 and 3 at the other end of the car. Do not compare the number of bounces
of the front with the rear; they are often different.

A car with no more than one or two bounce oscillations after releasing the bumper at
each corner of the car and with smooth, quite operation probably has good springs and shock
absorbers, if the height and ride quality are good. Unusual or excessive noises, differing
number of bounce oscillations at each side of the car, or excessive bouncing indicates a need
to follow up the bounce test with one of the remaining tests.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 57

ASSESSMENT TASK LO1-2

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 58

OPERATION SHEET LO1-2

OPERATION TITLE : CHECK SUSPENSION RIDE HEIGHT

PURPOSE :

A suspension ride height check is a simple and quick way to determine if the car is too
low; weak, sagging springs let the suspension height drop.

EQUIPMENT TOOLS AND MATERIALS:

• Vehicle equipped with suspension system

PROCEDURE:

1. Park the car on a smooth level surface; the ramps of a wheel alignment rack are ideal
because they are level and allow easy access to the suspension members.

2. Check for unusual amounts of weight that might be in the trunk or backseat of the car. Hey
should be removed or allowances made for any added weight; ride height specifications are
given for unloaded cars.

3. Check the tire pressure and correct it, if necessary. Note whether the tires are stock size; if
not, allowances must be made in the checking dimensions.

4. Obtain the ride height specifications and the locations of the measuring points.
5. Measure the distances at each measuring point and compare them with the specifications.

Sagged springs are indicated if the measured distances are shorter or lower than the
specifications.
6. Compare the left and right measurements; they should be almost equal.

When one side of the car sags
more than the other, it is necessary to
determine whether the lean is caused by
a weak front spring, a weak rear spring,
or both; either will cause this problem
(Fig. 2).

Figure 2. This vehicle is probably leaning because of a weak
right front or rear spring; Lifting the car in the exact center at
the front or rear will usually show if it is the front or the rear
spring that has sagged.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 59

Figure 3. Ride height measurements are made at different locations as determined by the vehicle manufacturer.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 60

ASSESSMENT TASK LO1-3

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO

1. Selected and used tools and testing instruments for the job
(appropriateness)

2. Observed the procedures correctly

3. Observed safety in performing the job.

4. Observed cleanliness/orderliness during and after the performance

5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 61

JOB SHEET LO1-2

CHECK BALL JOINTS

Ball joint boots are checked visually (Fig. 4); the area behind the boot and ball joint where
you cannot see can be checked by running your finger around the boot and feeling for problems
Look or feel for grease outside of the boot, which indicates breaks or tears. If the boot is torn,
the ball joint will probably fail, if it has not already, and should be replaced (Fig. 5). While
checking the boot, squeeze it to ensure that there is grease inside of the boot. An empty boot
indicates a need for lubrication.

Lubrication requirements for a ball joint vary among manufacturers. The lubrication
intervals for modern joints are rather long; one manufacturer, for example, requires lubrication
every 3 years or 30,000 miles (48000 Km). Long interval such as this makes it easy for the
average motorist to forget about lubricating ball joints completely. Low friction ball joints are
permanently sealed and require no further lubrication.

‰ Checking a Wear Indicator Ball Joint
for Excess Clearance

To check a wear indicator ball joint for
excessive clearance, you should:

1. Park the car on a level surface Figure 4.
Depending on the suspension type and
where the spring is located, a ball joint is
either (A) a load-carrying or (B) a
friction-loaded type that allows access to
the lower control arms and ball joints.
The ramps of an alignment rack are
ideal. The weight of the car should
remain on the tires.

2. Wipe off any grease or dirt on the Figure 4. Depending on the suspension type and where
checking surface or the lower face of the the spring is located, a ball joint is either (A) a load-
ball joint. carrying or (B) a friction-loaded type.

3. On some styles, slide a plain flat
screwdriver or other flat, metal object
about ¼-1/2 in. 6-12 mm) wide across
the bottom surface of the ball joint; it
should bump into the checking surface.
If the checking surface has moved up
into the ball joint, the ball joint is
excessively loose and should be
replaced.

Figure 5. A cut or torn ball joint boot will let the grease
escape and allow dirt and water to enter the joint; if the

joint is not already worn out, it will soon fail

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 62

4. On some styles, grip the grease fitting
with your fingers and try to rotate it; if the
grease fitting can be rotated, the ball
joint is excessively loose and should be
replaced (Fig. 6).

• Checking a Load-Carrying Ball Joint
on a Lower Control Arm for
Excessive Clearance (Fig6).

When the vehicle load passes from the Figure 6. If the grease fitting can be easily rotated
spring and through the lower control arm to on some ball joints, the joint is worn out and should
the steering knuckle, the lower ball joint is
the load-carrying ball joint. This is true in be replaced.
cases where either a torsion bar, coil spring
or air spring is attached to the lower control Figure 7. When checking the clearance of a load
arm. This load squeezes a compression carrying ball joint, the load of the vehicle must be
loaded ball joint tightly between the control removed from the ball joint using a jack placed in
arm and the steering knuckle or tries to pull the correct location depending on whether the load-
a tension loaded joint apart. The ball joint carrying joint is the lower or upper one. Note the
must be unloaded to measure the amount of support wedge that is used when the load-carrying
clearance in the ball joint. This is usually
accomplished by lifting the car by the lower joint is on the upper arm (right).
control arm so the spring s compressed. If
the car was lifted by the frame, the spring
would push the lower control arm downward
until the rebound/extension bump stop
contacted the upper control arm. In this
position the spring pressure holds both ball
joints tightly. The ball joints appear to have
zero clearance.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 63

ASSESSMENT TASK LO1-4

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 64

JOB SHEET LO1-3

CHECK KINGPIN CLEARANCE

Figure 8. Kingpin clearance is measured by mounting a dial indicator as shown and
moving the bottom of the tire in and out while watching the amount of travel on the dial

indicator.

Although kingpins are not ball joints, they have been included with these checks because a
kingpin performs a similar function and the checking method is similar. Kingpins are used on
solid axles and some twin I-beam axles; they are normally checked by measuring the side
shake of the tire.

To check a kingpin for excessive clearance, you should:

1. Raise and support the vehicle on a hoist or jack stands.
2. Eliminate wheel bearing clearance by installing a brake pedal jack to apply the brakes or

by tightening the spindle nut.
3. Position a dial indicator at the lower part of the tire with the dial indicator stylus in a

horizontal position (Fig. LO1-2a).
4. Push in and out on the tire while observing the dial indicator readings. Worn kingpins are

indicated if there is more than:
a. ¼ or 0.250 inch (6.35 mm) of side motion on 16 inch or smaller wheels.
b. 3/8 or 0.375 inch (9.5 mm) for 17 inch to 18 inch wheels.
c. ½ or 0.500 inch (12.7 mm) for wheels larger than 18 inch.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 65

ASSESSMENT TASK LO1-5

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 66

JOB SHEET LO1-4

CHECK CONTROL ARM BUSHINGS

Worn suspension bushing allows the
control arm to move inward and outward or
forward and backward as well as up and
down. This results in an alignment change of
the tires which in turn, will cause tire wear and
handling difficulties. This looseness often
causes suspension noises, usually “clunks”
when driving over rough roads or when the
brakes are applied. Faulty rubber control arm
bushings can usually be seen during a visual
inspection. In locations where the bushings
are difficult to see, faulty bushings are
identified by excessive control arm motion
through either an in-and-out or a sideways
direction.

To check rubber control arm bushings, you
should:

1. If possible, check the upper control arm Figure 9. These faults indicate control arm
bushings from under the hood. Use a bushings that need replacement.
light so you can get a good look at the
rubber parts of the bushing. Ignore
small, light cracks as long as the rubber
is still solid and resilient. Look for heavy
cracks, rubber material breaking out, or
rubber distortion, which allows the
control arm to change position. The
pivot bolt should be centered in the
bushing. Bushings that are distorted,
breaking up, or getting ready to break
up should be replaced (Fig. 9).

2. Raise and support the car on a hoist or
jack stands.

3. Visually check the bushings on the Figure 10. A badly worn metal control arm bushing
lower control arm, looking for the same and shaft. Note the worn, shiny areas on the
sort of problems Also, check the sides control arm shaft
of the control arm and the frame metal
next to it for signs of metal contact,
which indicate bushing failure.

4. Swing the tire rapidly back and forth while forcing it to bump at the steering stops; also,
force the tire in and out. While doing this, watch the control arm for any motions that
would indicate bushing failure.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 67

5. On single lower control arms, try prying the inner end of the control arm sideways using a
pry bar or large screwdriver. A slight motion is acceptable; larger motions indicate weak
bushings.

To check metal control arm bushings, you should:

1. Bounce the suspension while listening for squeaks or other bushing related abnormal
noises. If possible, place our finger lightly on the bushing while bouncing the front end; a
noisy bushing will often have a rough, harsh feel. Noisy bushings can sometimes be
cured by greasing them, but if they have squeaked for very long, they are probably worn
and should be replaced.

2. Raise and support the car on a hoist or a jack stands.

3. Swing the tire back and forth rapidly, so the turning stops strikes rather hard, and watch
the control arm bushings. A very slight amount of side motion is acceptable, but a
definite motion or jumping of the control arm on the shaft indicates a faulty bushing.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 68

ASSESSMENT TASK LO1-6

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 69

JOB SHEET LO1-5

CHECK STRUT ROD BUSHINGS

Strut rod bushings are rubber bushings that
are compressed tightly against each side of an
opening in the frame bracket. If they become
weak, the outer end of the lower control arm
will have an excessive amount of travel in a
forward and backward direction.

Strut rod bushing failure is often indicated
by a “thump” or “clunk” as the brakes are
applied. These bushings are checked visually.

To check strut rod bushings, you should:

1. Raise and support the car on a hoist or
jack stands.

2. Grip the bushing end of the strut rod
and shake it up and down; any free play
indicates a faulty bushing.

Inspect the bushing for hard cracks, rubber
breaking, and severe distortion of the rubber;
also check for signs of contact between the
metal backup washer and the bushing bracket.
Any of these indicate a faulty bushing (Fig. 11)

Figure 11. Faulty strut rod bushing (A) allows the
outer end of the lower control arm to move forward

or rearward (B).

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 70

ASSESSMENT TASK LO1-7

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 71

JOB SHEET LO1-6

Occasionally, the tire on a strut suspension
shows excessive camber wear, which indicate
that the strut body or strut piston rod might be
bent. Several checks can be made to
determine if this has occurred.

One check is to compare the included
angle or the camber angle and steering axis
inclination angles with the specifications.

A quick check for a bent strut body is to
measure the distance between the strut body
and the brake rotor on both sides of the car
and compare the measurements. If they differ
by more than a few thousandths of an inch,
one of the struts is bent (Fig. 12).

Figure 12. A rubber ruler is being used to measure
the rotor-to-strut distance, checking for a bent

spindle or strut; this distance should be the same
on the other side of the car.

To check for a bent piston rod, loosen the piston rod at the upper mount and then rotate the
piston rod while you watch for side motion at the top of the tire or strut body. A good strut rod
should rotate evenly with no side motion of the tire or strut body.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 72

ASSESSMENT TASK LO1-8

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Selected and used tools and testing instruments for the job

(appropriateness)
2. Observed the procedures correctly
3. Observed safety in performing the job.
4. Observed cleanliness/orderliness during and after the performance
5. Observed time element.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 73

JOB SHEET LO1-7

ROAD TEST

A technician road tests the vehicle to confirm the nature of the problem and also to try to
determine the cause. Most technicians have a preferred test route that provides various bumps
and road surfaces and is away from heavy traffic. During a road test, the vehicle is driven in a
manner to try to simulate the particular problem. In other words, if you are checking for a noisy
shock, you want a rough road; if you are checking a pull condition or vibration problem, you
want a smooth road. Finding a good test route that is close to the shop can be difficult in many
metropolitan arrears.

While conducting a road test, you should observe the following guidelines:

‰ Make sure the vehicle is safe to operate by quickly checking the tires, brake pedal
operation, and steering wheel feel.

‰ Observe all pertinent traffic laws.
‰ Use the vehicle’s seat and shoulder belt.
‰ Drive the vehicle in a normal manner so you will not cause any additional wear or

damage.
‰ Note the operation of the ABS and airbag warning lights if the vehicle is so equipped.

During the test, the technician will try to accomplish the following:

‰ Confirm the customer’s complaint
‰ Pin down the problem area, front or back and right or left side.
‰ Determine the nature of the problem (i.e. noise, vibration, shake or pull)
‰ Determine whether the problem is vehicle speed sensitive and what speed it is most

noticeable, whether it is torque sensitive, and whether it is engine speed sensitive or
gear ratio sensitive.
‰ Determine whether it is a tire, suspension, steering alignment, or brake problem.

Note any unusual or unsafe condition to be brought to the attention of the owner.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 74

ASSESSMENT TASK LO1-9

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO
1. Performed pre-driving check-up.
2. Observed the correct procedures in warming-up the engine
3. Observed traffic rules and regulations.
4. Observed cleanliness/orderliness during and after the performance
5. Pinned-down the problem.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 75

Qualification : Automotive Servicing NC III

Module Title : Servicing Suspension System

Learning Outcome #2 : Dismount/mount suspension component parts

Assessment Criteria:

1. Suspension components are dismounted/mounted.
2. Dismounted parts are tagged/marked.
3. Parts are dismounted without causing damage to vehicle components.

Resources:

1. Vehicle with complete suspension system
2. Simulated workplace
3. Lifting equipment such as jack, lifter and stands
4. Suitable press tool for pivot bushings
5. Grease cap tool
6. Suitable ball joint stud remover
7. Pry bar
8. Hammers
9. Diagonal pliers
10. Spring compressor
11. CDs, Tapes, Transparency, Manual, Books
12. Basic hand tools

PREFERENCES:

Before performing the activities, be sure that you are skilled in the following:
• Observing safety practices in the workshop;
• Using jacks, lifts and hoists to lift the vehicle
• Maintaining auto mechanic’s tools and equipment.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 76

Learning Outcome #2: Dismount/mount suspension component parts.

LEARNING ACTIVITIES SPECIAL INSTRUCTIONS

• These activities will guide you in dismounting

and mounting suspension component parts.

1. Remove front suspension

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 77

JOB SHEET LO2-1

1. Remove an upper control arm
assembly on a lower control arm
mounted coil spring

a. Raise the vehicle. Figure 1.
• Place safety stands under Figure 2.
the frame.
• Place the jack under the Figure 3.
lower control arm. Get it as
close to the lower ball joint
as possible.

b. Remove the tire and wheel
assembly.

c. Remove the rebound bumper
from the upper control arm
(Figure 2). Do this by removing
the hold-down bolt.

d. Remove the cotter pin from the
ball joint stud (Figure 3).
• Use the diagonal pliers to
straighten the ends of the
cotter pin. Pull the eye from
the nut (Figure 4).

e. Loosen the nut on the upper
ball joint stud. Do not remove it
(Figure 3).

•

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 78

f. Break the ball joint loose Figure 4.
between the tapered ball stud Figure 5.
and the tapered hole in the
steering knuckle. Use method
number 1 (Figure 4).

• Use a special removing tool
to apply pressure to the ball
joint stud.Place the tool over
the lower ball joint stud.

• Use one wrench to hold the
adjusting bolt on the tool.
Use a second wrench to
turn the tool for tightening
and loosening (Figure 5).

• Tighten the tool until it is
under strong tension.

• Note: Do not attempt to break
the joint with tool force only.
This will damage the tool.

• Rap the stud area of the
steering knuckle sharply
with a hammer. Jar the joint
loose (Figure 6)

Figure 6.

g. Break the ball joint loose
between the tapered ball stud
and tapered hole in the steering
knuckle. Using method number
two (Figure 7).

• Place one hammer on one Figure 7.
side of the spindle. Place it
near the ball joint.

• Rap the other side of the
spindle with another
hammer sharply. This frees
the stud from the knuckle

Code No. Date: Developed Date: Revised Page #
79
ALT723315 Servicing and Repairing Suspension System June 4, 2004 March 1, 2006

h. Wire the brake and knuckle in place. This prevents brake hose damage.

i. Remove the nut from the stud.

j. Lift the upper arm from the knuckle.

Note: If only the ball joints are to be replaced, stop at this point.

k. Remove the upper control arm shaft-to-
bracket nuts and lock washers. Carefully
noting the number, thickness and location
of the adjusting shims (for correct
replacement) Figure 8.

l. Remove the control arm assembly. Pull it
away from the vehicle.

Figure 8. Shaft-to-bracket nuts.

2. Remove a lower control arm assembly on a lower control arm mounted spring.

a. Raise the vehicle and place under the
frame.

Note: The vehicle needs to be high enough off
the floor to allow the lower control arm to
swing down without striking the floor
(Figure 9).

Figure 9..

b. Remove the tire, wheel and drum
assembly.

c. Remove the shock absorber (Figure 10).

Note: On some models only disconnect the lower
end and push the rod all the way in.

Figure 10.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 80

d. Disconnect the stabilizer at the control arm Figure 11.
(Figure 11).

• Remove the nut from the bar end.
• Lift the bar away from the lower control

arm.

e. Disconnect the strut rod from the control
arm, if so equipped.

f. Disconnect the tie rod from the steering
arm.

g. Place a floor jack under the lower control
arm. Locate it parallel with the arm (Figure
12).

h. Raise the lower control outer end enough to Figure 12.
take the pressure off the lower ball joint Figure13.
(Figure 12). Figure 14.

i. Remove the cotter pin from the upper and
lower ball joint stud bolts (Figure 13). Use
diagonal pliers to straighten the ends of the
cotter pin and pull the eye from the nut
(Figure 14).

j. Loosen the lower stud nut approximately
two turns.

Note: Do not remove at this time.

k. Install the special ball stud bolt remover tool
(Figure 15).

• Place the tool over the top stud.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 81

• Adjust the bolt on the tool to fit snugly Figure 15.
against the lower ball stud. Figure 16.
Figure 17.
• Tighten the tool with one wrench while Figure 18.
holding the adjusting bolt with another
wrench (Figure 15).

• Tighten the tools until the studs are
under tension.

Caution: Do not attempt to break the joint with
tool pressure only. This could damage the
tool.

l. Tap the steering spindle sharply with a
hammer near the lower stud. This will
loosen the stud from the spindle (Figure
16).

Caution: Prevent the coil spring from slipping
by installing a spring compressor.

m. Remove the ball joint stud nut (Figure 16)

n. Lower the control arm slowly with the jack.

Caution: The coil spring is very dangerous
while under pressure. Use extreme care
when working with it.

o. Remove the jack from under the control
arm.

p. Remove the spring compressor.

q. Remove the control arm pivot bushing bolts
(Figure 18). Unscrew the nut and remove
the bolt on both pivot bushings.

r. Remove the lower control arm from the
vehicle.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 82

SELF-CHECK LO2-1

Remove Front Suspension Components
Directions: At this time, check your skills by reviewing the following criteria.

1. Remove the upper control arm assembly on a lower control arm mounted coil spring.
2. Remove the lower control arm assembly on a lower control arm mounted coil spring.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 83

ASSESSMENT TASK LO2-1

Your trainer will provide you with the necessary tools and equipment for the job, and
supervise you in your work; you will be graded based on the list below:

PERFORMANCE CRITERIA YES NO

1. Support the vehicle to unload the pressure on the ball joints.

2. Adjust the wheel bearings.

3. Check the ball joints.

4. Check the inner bushings on the control arms.

5. Check the strut rods and the stabilizer bars.

6. Remove the upper control arm assembly on a lower control arm
mounted coil spring.

7. Remove the lower control arm assembly on a lower control arm
mounted coil spring.

8. Observe all safety rules.

9. Use terms correctly to describe inspecting and removing suspension
components.

10. This task will be completed 5 times for each item.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 84

PERFORMANCE TEST

Learner's Name Date
Competency: SERVICE SUSPENSION SYSTEM
Test Attempt
1st 2nd 3rd

Directions: Level OVERALL EVALUATION
Achieved
CALL INSTRUCTOR, ask instructor to PERFORMANCE LEVELS
assess your performance in the
following critical task and performance 4 - Can perform this skill without supervision and with
criteria below initiative and adaptability to problem situations.

You will be rated based on the overall 3 - Can perform this skill satisfactorily without
evaluation on the right side. assistance or supervision.

2 - Can perform this skill satisfactorily but requires
some assistance and/or supervision.

1 - Can perform parts of this skill satisfactorily, but
requires considerable assistance and/or supervision.

Instructor will initial level achieved.

PERFORMANCE STANDARDS Yes No N/A
For acceptable achievement, all items should receive a "Yes" or
"N/A" response.

1. Is work completed without causing damage to any work place
property or vehicle?

2. Is correct information accessed and interpreted from appropriate
manufacturer specifications.

3. Are tests carried-out to determine faults using appropriate tools and
techniques?

4. Suspension system failure accurately identified and corresponding
repair works recommended.

5. Suspension system components checked for cracks, loose nuts, bolt
or bushing, and leak

6. Damaged parts accurately identified.

7. Cause of failure accurately identified (Conventional and Air
suspension)

8. Test conducted as per prescribed procedure.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 85

ASSESSMENT INSTRUMENT

EVIDENCE PLAN Automotive Servicing NC III

Competency Repair Suspension System
standard:
Ways in which evidence will be collected:
Unit of [tick the column]
competency:

The evidence must show that the candidate … Question/Interview
* Identified function of suspension system accordingly. Demonstration
Written
Types of suspension system identified and explained. Portfolio
Practical
Principles of operation of suspension system were explained and
identified.
Parts and components were identified and explained.
* Causes of failure accurately identified.

System failures were identified.

* Dismounting and mounting of suspension system components were
performed.

Suspension parts disassembled and reassembled properly.
No damage to parts, vehicle and equipment during disassembly and
reassembly.
Safety procedures observed and maintained.

Cracks, loose bolts and nuts, loose ball joints and bushing, and gear
oil leaks checked accordingly.
* Damaged parts are checked and replaced as per vehicle standards and
specifications.
Appropriate tools and equipment used.

Checked and adjusted suspension rebounding.

Troubleshoot suspension system parts and components.

Causes and remedies identified.

* Testing of suspension system operations conducted.

PERCENTAGE OF ACCOMPLISHMENT

NOTE: *Critical aspects of competency Date:
Date:
Prepared
by:
Checked
by:

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 86

GLOSSARY

A-Arms or wishbone – A suspension member used to determine the position of a steering
knuckle or axle, usually in a lateral direction.

Air suspension – A system in which air-filled, elastic springs are used in place of metallic
springs.

Antidive suspension – A suspension design to reduce amount of dive during braking.

Axle – A cross support for a vehicle that is designed to carry the weight of the car.

Bounce – Straight line motions of the sprung mass of a car in a vertical direction.

Bushings – A device that allows rotation or linear motion. It uses a sliding motion of the
internal parts.

Camber (positive or negative) – A vertical angle of the tire seen when viewing the tire from the
front or the rear; used primarily to reduce tire wear.

Caster (positive or negative) – An angle of the steering axis in which the top of the steering
axis leans forward or rearward; used primarily for directional control.

Chassis – The portions of a car hat remain after the body has been removed. It includes
suspension and steering systems.

Control arm – A suspension member used to determine the position of the steering knuckle or
axle, usually in a lateral direction.

Damped, Dampened – A force or action opposing a vibrating motion to reduce the amount of
vibration.

Dive – A pitching motion of the sprung mass of a car downward at the front that usually occurs
during braking.

Frequency – The speed at which an action occurs.

Friction – The resistance as one surface slides over another.

Hydraulics – A system that uses fluid under pressure to transfer motion and pressure.

Included angle – The angle between the camber angle and steering axis inclination.

Jounce – A bounce motion during which the tire travels upward, relative to the car,
compressing the spring and shock absorber.

King bolt, Kingpin – A sturdy steel shaft used to connect the steering knuckle to an axle. It
provides the pivot axis.

Panhard rod – A device that connects the axle to the frame; it controls sideways motions of the
frame or body.

Pressure – A unit of force applied on a given area.

Rebound – A bounce motion during which the tire travels downward relative to the car and the
spring and shock absorber extend.

Road test –Operation of the vehicle under conditions that are designed to recreate a particular
problem.

Shock absorber – A device, usually hydraulic, used to dampen or reduce the amount of spring
oscillations after a bump.

Short-long arms S-L A – A suspension system that uses a relatively short upper control arm
and a longer lower control arm.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 87

Spring – A flexible suspension member that allows bounce travel of the suspension

Spring rate – The change of load on a spring per unit of deflection.

Sprung weight –The total weigh of the portions of the car that are carried by the springs.

Stabilizer bar –A suspension member used to reduce body lean during cornering.

Steering axis – The line around which the front tires turn when the car turns a corner.

Steering Axis Inclination (SAI) – An angle of the steering axis in which the top of the steering
axis leans inward.

Steering knuckle –The front suspension component that attaches the front tires and wheels to
the steering axis and steering linkage.

Strut – A suspension system type hat utilizes the shock absorber as the upper tire position
locating member

Strut rod – A suspension member that is used to brace the control arm to keep it from moving
forward or backward.

Toe – An angle of the tire, relative to straight ahead, if viewed from above.

Toe angle - The actual amount that the tire differs from pointing ahead.

Torsilastic bushing – A bushing that allows motion through the elastic nature of rubber.

Torsion bar – A spring that allows suspension motion by twisting.

Watt’s link – A suspension member consisting of two rods and a pivoting bell crank that is used
to keep the body from moving sideways relative to the axle.

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 88

Learner’s diary

DIARY NOTES

Record important dates, jobs undertaken and other workplace events that will assist you in providing further
details to an Assessor.
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................
.................................................................................................................................................................

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 89

Record of Achievement

Module: Servicing Suspension System

LO 1 : Identify the types of suspension system, component and its operating principle
(Conventional and Air suspension).

Performance Criteria:
1.1 Types of suspension were identified, explained and differentiated.
1.2 Main component and functions of suspension system were identified.
1.3 Principle of operation of suspension system were explained and illustrated.

Comments:

..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................

Learner has satisfied the above performance criteria.
Learner signature: ........................................................................
Trainer signature: .........................................................................
Date: ............................................................................................

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 90

Record of Achievement

Module: Servicing Suspension System

LO 2 : Diagnose suspension system failure.

Performance Criteria:
2.1 Causes of failure were accurately identified.
2.2 System failure was properly identified.
2.3 Vehicle was properly lifted and jack stands were used.
2.4 Vehicle, workshop area, and equipment safety procedure were observed.

Comments:

..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................

Learner has satisfied the above performance criteria.
Learner signature: ........................................................................
Trainer signature: .........................................................................
Date: ............................................................................................

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 91

ACKNOWLEDGEMENT

Copyright TESDA
Centex: SOUTHERN ISABELA COLLEGE OF ARTS AND TRADES

First Published November 2003
This draft was prepared at the Competency-Based Learning Materials Development
Workshop conducted at the TESDA Women’s Center, from 23th to 27th October 2003.
It was based on the competency standard for Automotive Service Technician developed
by the Skill Standard and Certification Office (SSCO), and the Competency-Based
Curriculum Instructional Modules developed by the National Institute for Technical
Vocational Education and Training (NITVET), Technical Education and Skills
Development Authority (TESDA).
Some materials for contextual learning (science, math and communication) were
supplied by Academic Teachers from different TESDA-supervised schools.

This learning instrument was developed by the following personnel:

Technology Instructors:
1. Exsuperio G. Jacinto
2. Jeronimo L. de Jesus
3. Dante V. Balagot
4. Leopoldo P. Bueno

Academic Teachers:
1. Sonita Dr. Camacam
2. Llarena T. Ocampo
3. Elena C. Echija
4. Jovita P. Pasamic

Vocational School Supervisor:
™ Abraham B. Pascua

Facilitator:
™ Cesar G. Ancheta

This work was produced with funding provided by TESDA.

REFERENCE AND FURTHER READINGS:

1. Automotive Chassis Systems by: Birch, Thomas W.
2. Automotive Mechanics 10th Ed. by: Crouse and Anglin
3. Automotive Excellence
4. Hilton’s Truck & Van Repair Manual (93-97)
5. Oral Communication
6. Dictionary of Technical Terms

Code No. Date: Developed Date: Revised Page #
Servicing and Repairing Suspension System June 4, 2004 March 1, 2006
ALT723315 92