CASCADIA STEERING SYSTEMS -2013 Freightliner Cascadia Стр.

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STEERING

Cascadia Steering Systems (Rack & Pinion Steering Gear, ThyssenKrupp, LZS5)

SPECIAL TOOLS
SPECIAL TOOLS
Tool Number Tool Name
- Low Pressure Gauge, 200-300 psi (1380-2070 kPa) maximum
- Temperature Gauge
J-26487 (1) Power Steering System Analyzer (PSSA)
J-28593 (1) Power Steering System Analyzer Adpater Kit
J-37130 (1) Relief Valve Plug
JP1619N Renolit JP1619N Grease
PH-B10-2-A6P (1) 3/8 In. Female NPT Aluminum Relief Valve Threaded Cartridge
Body
PH 3/8 GG S (1) 3/8 In. NPT Pipe Coupling
PH-RAH101K30 (1) Aluminum Hydraulic Threaded Cartridge Relief Valve with Knob
PH 8-R6X-S (1) Swivel Nut Run "T"
PH-8STX-S (1), (2) Male JIC "T" with Male NPT Branch
WH-9100X8X6 (1) 3/8 In. Male NPT Swivel Adapter to 37 Degree Female JIC
14-12694-042 (1) 42 In. Power Steering Hose
23-11321-001 (1) 3/8 In. Male Connector to 5/8 In. Beaded Hose Barb
23-11470-088 (1) Straight Thread Connector with "O" ring
(1) Used for Internal Leakage Testing

(2) USe Steel 37 Degree JIC fittings only.

DESCRIPTION & OPERATION

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Fig. 1: Identifying Typical Rack & Pinion Steering System

GENERAL DESCRIPTION

l Steering gear pitman arm is connected to axle steering arm via a drag link assembly of fixed
length. At time of steering vehicle, ball stud and socket assemblies prevent binding when change
in relative angles of pitman arm and steering arm occurs.
l An integral part of fixed-length drag link, ball stud sockets cannot be moved. Ball studs and
sockets feature a dual-seat design.

SYSTEM OVERVIEW

Terms & Abbreviations

Bellow: A rubber or polypropylene "boot" clamped over ends of rack and inner tie rods on rack and
pinion steering gear.

I-Shaft: Intermediate Steering Shaft.

Poppet: Rising and falling valve having a disk at end of a vertically set stem. Poppet will decrease
power steering hydraulic pressure just before full right or left turns.

PSSA: Power Steering System Analyzer

General Information

Power steering pump is heart of power steering hydraulic system. Pump converts rotational energy of
engine into hydraulic energy, flow, and pressure. This hydraulic energy is then used by steering gear,
both integral, and rack and pinion to steer vehicle.

A partial vacuum at inlet is generated by power steering pump. This vacuum will cause atmospheric
pressure to push fluid into pump from reservoir. Pump then force fluid into system for use by steering
gear.

Pump output flow is related to steering gear speed, and pump output pressure is related to steering gear
force.

PRINCIPLES OF OPERATION

Two brackets are used to install rack and pinion steering system to front axle, and outer tie rods are
used to connect to tie-rod arms pivoting wheels. See Fig. 1. When steering wheel is turned,
intermediate steering shaft will turn input shaft. This will cause rotation of torsion bar and pinion gear
within rack housing. Twisting of torsion bar will cause power steering fluid to provide power aid,
through a rack-mounted piston, to pinion gear, moving rack. Tie-rod arms then moved by rack (with a
tie rod at each end).

THYSSENKRUPP RACK & PINION STEERING GEAR

l Rack and pinion steering system is located at front axle and mounted with two brackets.
l It is connected by outer tie rod to tie rod arms which causes wheels to rotate.
l Intermediate steering shaft rotates input shaft when steering wheel is turned.
l Torsion bar and pinion gear contained within rack housing rotates with input shaft.
l Torsion bar rotation causes piston movement in rack due to movement of steering fluid, and
provides a power assist to pinion gear. This causes rack to move, which in turn causes tie rod
arms movement.

ZF STEERING I-SHAFT

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ZF steering driveline is a ball-splined telescopic shaft equipped of a tube which has internal splines. It
also contains a special-pattern shaft having external splines. A ball bearing cartridge which contains
two rows of ball bearings is present at slip-end of tube. Bearings movement in splines produces a
positive rotating link. ZF steering driveline design is free from radial play but have a low-resistance
axial displacement with an effective stroke of ±1.10 inches (±28 mm). Ball-splined telescopic shaft
requires no maintenance, as it has a low wear rate.

COMPONENT LOCATION

Fig. 2: Identifying Typical Integral Gear Components

ON-VEHICLE TESTING
BALL STUD TESTING

WARNING: For safe vehicle operation, all steering mechanisms are necessary.
Hence given subject instructions must be followed, as neglecting
instructions may cause steering loss resulting in personal
injury/property damage.

l Turn steering wheel and inspect for looseness between ball stud end and pitman arm and steering
arm, and also in ball stud nut.
l Replace drag link (if ball stud end is movable), and nut and cotter terminal (if ball stud nut is
movable). For tightening ball stud nut use Torque Specifications.
l Push and pull drag link near pitman arm end laterally to inspect for any axial looseness in ball
stud end. Replace drag link if slackness is detected. NEVER drive vehicle, if axial looseness is
1/8 In. (3 mm) or more. Drive it only after drag link is replaced.
l Push and pull drag link near steering arm end vertically to inspect for any axial looseness in ball
stud end. Replace drag link if looseness detected. NEVER drive vehicle, if axial looseness is 1/8

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In. (3 mm) or more. Drive it only after drag link is replaced.

l Flush old grease from draglink by pumping in fresh grease.

ADJUSTING
ALIGNMENT PROCEDURE

A different alignment procedure from integral (recirculating ball) steering gears, are used by rack and
pinion steering. A calibrated, computerized, multi-wheel alignment machine is required for alignment,
operated by a skilled service technician.

1. Setup required for computerized alignment tool must be completed similarly as done for vehicles
with recirculating ball steering gears.
2. While wheels placed on turnplates, position rack travel center and align timing pointers on input
shaft seal cover and input shaft housing, as follows. See Fig. 3.

Fig. 3: Identifying Rack & Pinion Pointer Alignment

A. Move rack to right until it stops, then mark input shaft housing and input shaft seal cover.
B. Move rack to left, and count input shaft revolutions, using marks, until it stops.
C. Move rack to right for half the total revolutions, then line up pointers on input shaft seal
cover and input shaft housing.
3. Align steering rack on-center pointers each time alignment program requires that steering wheel
be pointed straight ahead. Clock steering wheel at end of procedure, not this time.
4. To get total specified toe-in dimension, each of outer tie rods required to be adjusted. Ensure total
toe-in is within 0 and 1/8 inch (3.18 mm), and target is 1/16 inch (1.58 mm). Tighten following
to:
A. Tie Rod Jam nut: 285-305 Ft. Lbs. (386-413 N.m).
B. Tie Rod Clamp nut: 30-36 Ft. Lbs. (41-48 N.m).

NOTE: Ensure maximum wheel cut is not above 46 degrees.

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5. To verify for interference between wheels/tires and other components, wheel must be turned all
way to right and left. Minimum clearance must be 1/2 inch (13 mm) from any fixed object, and
3/4 inch (19 mm) from any moving object.

NOTE: All spline/pinch bolt connections between steering gear and last U-
joint in column fit in only one position, so it is not possible to
reclock splined connections after alignment.

6. Steering wheel must be within 10 degrees of center as indicated in Fig. 4 If not, remove and
center wheel, using following procedure.

Fig. 4: Identifying Steering Wheel Centered

A. Deactivate airbag (if equipped in vehicle) and remove airbag module. Remove horn button
by prying it out around edge if air bag is not in vehicle.

NOTE: There is no threaded wheel-puller holes in steering wheel.

Tapered fit between steering wheel and column is designed to
be released by hand.

B. Loosen nut securing steering wheel on steering column, but leave it on shaft until wheel is
released from tapered fit.
C. Strike wheel upward from below at rim/spoke intersections, remove wheel using both
hands.
D. Remove and dispose of steering wheel nut, and install and put steering wheel center.
E. Install and tighten NEW steering wheel nut to 33-41 Ft. Lbs. (45-55 N.m).
F. Install and reactivate airbag (if equipped in vehicle). Install horn button if no airbag is
present in vehicle.

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TROUBLESHOOTING
POSSIBLE CAUSES FOR MALFUNCTION

l Overheating.
l Contaminated Fluid.
l Exterior Damage.
l Incorrect alignment.
l Components not adjusted properly.
l Too much System Restriction.

STEERING SYSTEM TROUBLESHOOTING

1. Tire pressure and load inspection.

A. Ensure front tires are inflated to proper pressure, and there is equal tire pressure on both
sides.
B. Ensure rear tires are inflated to correct pressure, and there is equal pressure tire pressure on
both sides.
C. Tire sizes must be correctly matched, and whether duplex or oversized tires (that were not
originally specified for vehicle) are installed.
D. Determine if vehicle operation is done at or over its rated load.

Verify if any problems found with tire pressure and load.

If tire pressure and load has problem, evaluate steering system complaint again.

If no problem is detected, next step.

2. Verify lubrication and condition of 5th wheel.

A. Verify if 5th wheel is properly lubricated.
B. Inspect plate surface for burrs, gouges, and irregularities.

Verify if any problems found with 5th wheel.

If 5th wheel contain problem, evaluate steering system complaint again.

If 5th wheel has no problem, go to next step.

3. Inspect for loose and binding components, indicating maintenance or adjustment of steering
components.
A. Inspect steering column bearings and U-joint for binding.
B. Inspect steering I-shaft U-joints and slip section for looseness or binding.
C. Inspect for excessive lash in steering system.
l With vehicle on ground and front tires pointed straight ahead, move steering wheel
until front wheels indicates slight movement.
l Align a reference mark on steering wheel to a rule, then slowly rotate steering wheel
in opposite direction until motion is again noticed at wheels.
l Inspect lash (free play) at rim of steering wheel.

NOTE: Steering wheel movement above 2-1/2 inches (64 mm) with a
20-inch (508-mm) steering wheel will cause excessive lash.

D. Ensure front wheels self-return without binding (integral gear only).

l With engine off, chock rear-most tires and put front tires on radius plates

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(turntables). Disconnect drag link from steering arm.

l Using hand, pull tire to one axle stop and release. Tire must self-return to almost
straight ahead.
l Repeat in opposite direction. If tire does not return to near straight ahead, inspect for
binding or a lack of lubrication in steering axle kingpin bushings or tie rod linkage.
l Connect drag link and tighten castle nut, then install NEW cotter pin.

E. Inspect for wear and looseness in all suspension fasteners and components.

Verify if any problems found with loose or binding components.

If problem found, fix problem by performing maintenance or adjustments as required.

If no problem found go to next step.

4. Prepare power steering system for temperature and hydraulic inspections.

A. Park vehicle outside to reduce noise and exhaust in shop. Record if fluid level was okay or
if fluid was added.
B. Install PSSA between pump high-pressure line and steering gear. As needed, fill and bleed
steering system.
C. Put temperature gauge in fluid reservoir, identify initial power steering fluid temperature.
Write down initial fluid temperature, and leave temperature gauge in reservoir for rest of
these tests.

CAUTION: Load valve should not be left fully closed for more than 5
seconds, this could damage power steering system.

D. Increase power steering fluid temperature up to normal operating temperature.

l Operate engine at idle, close load valve partially on PSSA until pressure gauge reads
1000 psi (6895 kPa).
l Open valve if fluid temperature reaches about 180°F (82°C).

Verify if power steering fluid is at or near 180°F (82°C).

If fluid is at or near this specification go to next step.

If not at or near this specification, close load valve partially on PSSA again until fluid
temperature is 180°F (82°C).

5. Test power steering hydraulic system.

A. Inspect total system back pressure.
l Operate engine at idle and ensure PSSA load valve is fully open.

l Read pressure gauge on PSSA and record total system back pressure.

NOTE: Total system back pressure above 100 psi (689 kPa) indicates
excessive back pressure. Go to step 8 to identify restrictions
in system.

B. Inspect for erratic pump response.

l Close load valve slowly, read pressure gauge if valve is completely closed.

l Open valve.

Rapid increase in pressure, appears to be uncontrolled, or rises above relief pressure, open
load valve immediately. See Specifications.

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Record whether pump response was erratic or not. Replace power steering pump if erratic,
and A and B again. Temperature must be about 180°F (82°C). Go to next sub-step if
pressure was consistent

C. Inspect pump relief pressure.

l Close load valve slowly and read pressure gauge when completely closed.

l Open valve and record relief pressure.

If pump relief pressure matches relief pressure in Specifications, if okay. Go to next sub-
step.

If pump relief pressure does not match relief pressure in Specifications, see pump
manufactures service literature to verify precise relief pressure for power steering pump
being diagnosed.

If pump relief pressure does not match relief pressure in Specifications or pump
manufactures specifications, replace power steering pump. Repeat sub-steps when power
steering pump is replaced A, B, and C.

D. Test pump relief valve reaction at idle.

l Operate engine at idle and record flow rate with load valve open.

l Close load valve until pump relief pressure is reached. Flow must drop to zero.

l Smoothly and quickly open load valve and record flow rate. Perform this procedure
3 times until it returns to flow rate recorded above.
l Determine whether operation relief valve operates correctly or incorrectly.

Relief valve is okay if flow rate returns smoothly and quickly. Move to next sub-step.

NOTE: If flow rate does not return smoothly and quickly, valve
operation is not correct. Replace power steering pump.

E. Test pump relief valve reaction at 1500 RPM.

l Run engine at 1500 RPM and note flow rate with load valve open. Close valve until
pump relief pressure is achieved.
l Smoothly and quickly open load valve and note flow rate. Do this procedure 3 times
until flow rate recorded above is reached.
l Record if relief valve operation is correct at 1500 RPM.

Relief valve is okay if flow rate returns immediately. Then move to next step.

NOTE: Valve operation is incorrect if flow rate does not return

immediately. Replace power steering pump.

F. Test flow of pump at idle with load applied.

l Operate engine at idle. Close load valve (slowly) so pressure gauge reads 1800 psi
(12 410 kPa).
l Read flow gauge and record flow rate. For high-pressure steering gears, apply 2300
psi (15 858 kPa) as test load pressure. See Specifications for minimum flow rate.
l Open load valve.

G. Test maximum flow of pump without applying any load.

l Operate engine at 1500 RPM.

l Read flow gauge and record maximum flow.

If flow rate is less than minimum specification indicated in Specifications, replace pump.

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Replace power steering pump if flow rate is more than 8 GPM (30 L/min).

CAUTION: When performing below test, ensure temperature is not

exceeding 250°F (121°C). If temperature exceeds, stop
test and write down last recorded temperature.

H. Note maximum fluid temperature.

l Operate engine at governed speed.

l Monitor power steering fluid temperature for 60 minutes, or until there is no change
of temperature for 5 minutes.
l Record maximum power steering fluid temperature.

During test, if temperature does not goes above 250°F (121°C), extreme system heat may
be not the cause of complaint.

If, at any time during test, temperature goes above this specification, system is operating at
excessive temperature levels, and may affect steering system performance and life.

Overtemperature problem will cause if there is excessive steering system back-pressure or

pump flow. Go to step 8 if there is restriction in system.

WARNING: When performing below test, ensure fingers are not

close to stop bolt and spacer block. Spacer block must
contact axle stop squarely, otherwise bolts could break
or block could eject causing personal injury.

CAUTION: When performing following test, steering wheel should

not be hold in full-turn position for more than 5 seconds
otherwise pump will damage.

NOTE: Use next step only for integral steering gears. Skip next step if
vehicle has rack and pinion steering.

I. Verify integral steering gear internal leakage.

l Operate engine at idle with load valve open.

l Put unhardened steel spacer, 1-inch (25-mm) thick, between axle and stop bolt at one
side of axle. There should be an extension or handle in spacer. Ensure handle is long
enough to keep fingers away from axle stop area. Use brazing rod or welding rod.
l Using assistance, rotate steering wheel until stop bolt contacts spacer block.

l Apply a 20-Lb. (89-N) force on steering wheel. Read internal leakage rate on flow
meter and record this value.
l Repeat this step (beginning with inserting spacer between axle and axle stop) for
opposite turn. When needed, replace steering gear components if leakage is greater
in either turn direction.

NOTE: 1.0 GPM (3.8 L/min) is maximum allowable internal

leakage for a single integral gear.

Verify if all power steering hydraulic tests provide good results.

If test result is correct, continue testing either poppet relief valve and stop bolt adjustment.

If test result is not correct, do repairs as required.

6. Inspect steering gear poppet relief valve and stop bolt adjustment (Integral gear only).

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A. Pitman arm must be positioned on steering gear sector shaft correctly. Ensure timing mark
on arm is lined up with mark on sector shaft.
B. Verify steering system for proper turn angle. Ensure stop bolt settings limit steering travel
so there is 1/2-inch (13-mm) clearance from all stationary components, and 3/4-inch (19-
mm) clearance from all moving components.

NOTE: When front wheels move toward stop bolts poppets will limit
steering assist. If adjustment is not correct, excessive force
could applied to steering linkage, or support will loss when
steering wheel approaches either full-left or full-right turns.

CAUTION: When obtained power steering pump relief pressure with

steering wheel at full lock, release wheel from this
position. DO NOT let pump relief pressure to be
maintained for longer than 5 seconds, pump may
damage.

C. Verify poppet relief pressure (integral gear only).

l Set up a system for hydraulic inspections, see step 4 for further detail.

l Fluid temperature must be approximately 180°F (82°C). Vehicle must be stationary

on ground with front wheels pointing forward.
l Operate engine at idle with load valve open. Move steering wheel to either full-lock
position and note pressure gauge reading.
l Do previous 3 instructions again for opposite turn and record poppet relief pressure.

Before steering stops make contact, pressure must drop slightly. If pressure increases (from
contact with steering stops), reset poppets/plungers manually.

If pressure is relieved and assist is lost when wheel is too far from axle stop, adjust
automatic poppet valve using instructions in next sub-step.

D. Set poppet valves (integral gear only).

l Rotate steering wheel to full lock position. Then 20-pound (89-newton) force on
wheel in this position.
l Use these instructions again for opposite turn.

If poppets adjustment is done or reset properly and, after subsequent vehicle operations,
loss of assist continues to occur if wheel is too far from axle stop, poppets have become
loose caused by previous incorrect poppet adjustment and require replacement. When
poppet is replaced and adjusted, retest for correct poppet relief function and record
pressure.

E. Ensure steering is adjusted to be on center.

l For rack and pinion steering, ensure tires are aligned straight ahead and timing mark
on gear housing is lined up with mark on input shaft seal cover. Align rack and
pinion steering system if it is not in 5 degrees.
l For integral steering gear, pitman arm must be aligned with sector shaft.

Verify if steering gear poppet relief valve and stop bolt adjustment test is normal.

If test is normal go to next step.

If test is not normal do repairs as required.

7. Inspect for abnormal power steering noise.

A. If steering noise already verified, inspect for proper fluid level. Record results.

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B. Inspect condition of power steering fluid and record condition.

C. Verify if a hissing sound is heard at less than full turn. If heard, inspect integral steering
gear (if appropriate) poppet and axle stop adjustment and record results.

See System & Component Restrictions - Troubleshooting and Specifications for possible
causes and remedies for common noises associated with power steering system and power
steering pump.

Verify for abnormal power steering noise.

If steering noise is abnormal, separate cause of problem, and repair as required.

If noise is not abnormal go to next step.

8. Inspect for leaks and restrictions, and test system back pressure.
A. Inspect for leaks and restrictions.
l Operate engine at idle.

l Inspect all hoses and fittings for kinked or collapsed hoses, or leaking fittings.
Inspect all external seals, mainly steering gear input shaft seal.
l Repair all leaking fittings and replace components as required. Any leaking seals
must be replaced.
l Inspect seal bores and sealing surfaces for scrapes or burrs. Ensure for proper
installation of seals with recommended tools.
l Kinked or collapsed hoses, or leaking fittings or seals must be recorded.

After replacing steering gear input shaft seal, it seal is found excessively hard, verify
system operating temperature, do sub-step 5.8 (if earlier not performed).

CAUTION: DO NOT move steering wheel or let system pressure to

go above rating of gauge when performing following
test. Doing so could damage gauge.

B. Verify system back pressure.

l Install a low-pressure gauge, 200 - 300 psi (1380 - 2070 kPa) maximum, between
pressure line and pump.
l Operate engine at idle and inspect for correct fluid level, add fluid if required. If
reservoir indicates bubbles or foam, inspect hose fittings for looseness or leaks.
l Read total system back pressure on pressure gauge while engine is at idle. Record
this value.
l If total system back pressure is above 100 psi (689 kPa), move to next sub-step.
Restriction is not cause of problem when pressure between pressure line and pump is
less.
C. Subtract values in system & component restrictions - troubleshooting table to identify
restriction of individual components. Record values for use later.

Inspect pressure at key locations in steering system to identify components at fault. While engine
is at idle, use low-pressure gauge and hose connection adapters required to measure pressure at
all locations. Whenever gauge moves to NEW position, fluid level must be correct, and air
should be removed at idle.

NOTE: Below refers to data in system & component restrictions -

troubleshooting table.

l Between pump outlet and pump-to-gear hose. Record as P2.

l Between pump-to-gear hose and steering gear inlet port. Record as G1.

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l Between steering gear outlet port and gear-to-reservoir hose. Record as G2.
l Between gear-to-reservoir hose and reservoir inlet port. Record as R1.
l Between reservoir outlet port and reservoir-to-pump hose. Record as R2.
l Note total system back pressure as determined in test 8. If maximum allowable restriction
(listed for each component) exceeds, use applicable action to take in Power Steering
System Noise - Troubleshooting and Power Steering Pump Noise - Troubleshooting.

POWER STEERING SYSTEM NOISE - TROUBLESHOOTING

Symptom Remedy
Growling or other abnormal steering Verify fluid level and inspect for air
noise. bubbles or foam. Ensure there is no hose
and fitting leaks. Add fluid if required if
fluid has air, inspect for inlet tube/hose
leaks. All leaks must be corrected.
Change from normal pump sound. Inspect power steering fluid reservoir.
Inspect for air bubbles or foam in fluid.
Verify for inlet tube/hose leaks if fluid
contain air. All leaks must be corrected.
Clicking sound during a turn. Inspect for loose steering components.
Inspect front suspension for inadequate
spring pin shims. Any loose steering
components must be tightened. Add front
spring pin shims if required.
Hissing if steering wheel is at or near full Hissing noise arise when fluid flows past
turn. a poppet valve. This is normal, no action
is required.

POWER STEERING PUMP NOISE - TROUBLESHOOTING

Possible Cause Remedy
Plugged intake line. Drain system and clear intake line if
required. System must be filled.
Presence of air leak at pump connections, Verify all connections for looseness, and
fittings, reservoir connections, shaft seal, all hoses for cracks. Tighten all
or power steering hoses. connections as required. Replace pump if
problem still exists. Replace hoses as
required.
Misaligned pump input shaft. Replace power steering pump.

SYSTEM & COMPONENT RESTRICTIONS - TROUBLESHOOTING

Total System and
Component Restrictions Maximum Allowable Action to Take
P2 = Total System 100 psi (689 kPa) Inspect pressure at key
locations.
P2 - G1 = Hose: Pump-to- 12 psi (83 kPa) Inspect for a kinked or
Gear plugged hose. Replace hose
if required.
G1 - G2 = Steering Gear 55 psi (379 kPa) Replace gear.
G2 - R1 = Hose: Gear-to- 12 psi (83 kPa) Inspect for a kinked or
Reservoir plugged hose, replace hose
if required.
2 qt: 4 psi (28 kPa) Replace filter and inspect
R1 - R2 = Reservoir
9 qt: 8 psi (55 kPa) for internal blockage.
Verify for a kinked,
R2 - P1 = Hose: Pump
12 psi (83 kPa) collapsed, or plugged hose.
Supply
Replace hose if required.

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Verify for presence of any leaks, restrictions, or excessive system back pressure.

If such conditions found, repair as required.

If such conditions not found, power steering system diagnostics is done. If further symptoms are
observed, evaluate system again as required.

RACK & PINION TROUBLESHOOTING

1. Do visual inspection of rack and pinion gear and hoses. Use following list to remedy specific
problems with gear or hoses:
A. Inspect rack and pinion bellows:
1. Remove bellow and inspect rack if bellow is torn. Replace bellow if rack has no
corrosion. Replace rack and pinion gear if corrosion found.
2. If fluid leaks from bellows, there is a internal leakage from\rack and pinion gear.
Replace leaking component.
B. Inspect metal tubes (transfer lines) on rack and pinion gear: Replace gear if tubes are
damaged, bent, or leaking.
C. Inspect power steering hoses for rubbing or chaffing:
1. Inspect for proper clearance to tires and axle. Adjust routing as required.
2. Inspect wheel size for approval with rack and pinion. Replace hoses as required.
D. Inspect tie rod arms for bending or breakage: Replace steering gear if tie rod arms are bent
or broken.

Verify if visual inspections expose a problem with rack and pinion gear.

If problem found repair as required.

If problem not found; go to next step.

CAUTION: Use care when PSSA is installed at high pressure inlet to rack
and pinion gear. Metal tubes below inlet port can damage
easily.

2. Inspect working/relief pressure of gear.

A. Install PSSA if previously not done.
B. While engine is running, move steering wheel to one side to full lock position.
C. Inspect system pressure at full lock position.
D. Rotate steering wheel to other side to full lock position.
E. Measure system pressure at other full lock position.

Verify if gear relief pressure is 2250 psi (15 520 kPa) or below on both sides.

If gear relief pressure is normal, go to next step.

If pressure is not normal, replace rack and pinion gear.

3. Troubleshoot based on following symptoms:

A. I-Shaft binds/sticks/seizes, or U-joints loose: Verify steering column front wall bearing.
Replace I-shaft, if required.
B. Rack hangs up/sticky/binds: Replace gear if it is not U-joints/driveline or pump.
C. Steering shudders:
1. Bleed system and lift front of vehicle off ground.
2. Slowly turn steering wheel from lock to lock frequently while engine is off.

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3. Fill fluid reservoir and turn from lock to lock again with engine off.
4. Start vehicle, then turn from lock to lock. Ensure fluid has no air bubbles.
D. "Lumpy" steering: yoke adjustment nut may be misadjusted, or I-shaft incorrectly phased;
replace gear. Do inspection of part number first on I-shaft, and ensure correct I-shaft is
installed.
E. Vehicle pulls to one side, but alignment is OK; possible torsion bar bias:
l If not installed earlier, install PSSA and start engine.

l Verify and note static pressure.

l Turn slightly to left and record static pressure, then turn slightly to right and note
static pressure. If pressure lowers when steering, torsion bar is damaged. Gear
replacement is required.

Verify if any of above symptoms found.

If either symptoms found, repair as required.

If either symptoms not found, diagnostic of power steering system is done. If further symptoms
are found, evaluate system again (as required).

REMOVAL & INSTALLATION

BALL STUD COVER

Removal

1. Remove drag link.

NOTE: Ensure proper care during removal of ball stud cover using
screwdriver to prevent damage to forging's sealing surface.

2. Remove cover from ball stud socket assembly by pressing cover's flanged portion with a
screwdriver.
3. Remove dirt from ball stud and socket throat, using clean cloth.

Installation

1. Apply chassis grease NLGI Grade 2 (8% 12-hydroxy lithium stearate grease) to socket throat and
ball stud. Fill NEW ball stud cover completely to 3/4 with NLGI Grade 2 grease.
2. Position ball stud perpendicular to socket stem by placing socket assembly in a vise or press.

NOTE: NEVER install ball stud cover using any sharp-pointed tool
(screwdriver, chisel, or punch) as these tools may damage cover.

NOTE: Stud cover can be installed using tube section whose inside
diameter is nearly equal to outside diameter of stud cover. Ensure
inside edge of tube to be chamfered (angled) to prevent rubber stud
cover from being cut.

3. Press NEW stud cover with tubing section. For cover to be in place, cover's flanged portion
should be seated on socket forging's sealing face.

NOTE: During installation, NEVER press seal using excessive pressure to

prevent incorrect sealing and cover deformation.

4. Install drag link.

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BELLOWS

Replacement

1. Park vehicle (on a level surface), turn off engine, set parking brake and chock tires. Open hood.
2. Loosen jam nut for driver side and loose tie-rod clamp for passenger side. Number of exposed
threads, and position of outer tie rod must be noted, for use upon installation.
3. Remove outer tie rod. See Fig. 1.
4. Remove small and large Oetiker bellows clamps, then remove bellows.
5. Inspect rack for corrosion or evidence of hydraulic fluid. Replace rack and pinion gear if either
found.
6. Install NEW small and large Oetiker bellows clamps onto bellows, but DO NOT tighten them.
7. Install bellows onto gear, and ensure its proper seating on housing and tie rod.
8. Secure small and large Oetiker bellows clamps.
9. Install jam nut for driver side, and install outer tie rod.
10. For Both sides, tighten jam nuts to 285-305 Ft. Lbs. (386-413 N.m), and tighten clamp nut to 30-
36 Ft. Lbs. (41-48 N.m).
11. Align rack and pinion.

DRAG LINK

Removal

1. Point front tires straight ahead. If possible, drive vehicle in a straight line for a short distance,
stopping at spot where service work will be done. NEVER change straight-ahead position of tires
during removal of drag link.
2. Set parking brakes. Block rear tires.
3. Tilt hood.
4. Remove ball studs cotter terminals and castle nuts, from both draglink ends. See Fig. 5.
5. Remove ball studs from axle steering arm and pitman arm with a ball stud removal tool.
6. Inspect for damage in ball stud cover and replace cover (if needed).

Installation

1. Insert ball stud at axle-end up through axle steering arm's bottom. Install castle nut and finger-
tighten it.
2. Align hole in pitman arm's lower end by turning steering wheel. Insert ball stud in pitman arm.
Install castle nut. See Fig. 5.
3. Tighten installed castle nuts to: 3/4-16; 90-170 Ft. Lbs. (122-230 N.m) and 7/8-14; 160-300 Ft.
Lbs. (217-407 N.m).

Tighten nuts (if needed) until nut slot and ball stud hole are in alignment. NEVER align nut with
cotter terminal hole.

4. Install and lock a NEW cotter terminal in all ball studs and nuts.

WARNING: Install and fasten NEW cotter terminals in ball studs and nuts.
Ignoring this warning may cause components to disengage
leading to loss of control on steering, which may cause
personal injury and property damage.

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Fig. 5: Identifying Typical Drag Link Components

5. Determine need for drag link lubrication by inspecting vehicle maintenance manual. Follow
maintenance manual instructions.
6. Inspect axle stop settings, and adjust (if needed).
7. Inspect steering gear poppet valves settings, and adjust settings (if needed), using instructions
given in concerned steering gear section in this group.
8. Steering wheel spokes on an unloaded vehicle (while its front tires point straight ahead) should
be within ± 10 degrees of center as shown here Fig. 6. Remove steering wheel and install spokes
in proper place if spokes are out of limit.

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Fig. 6: Identifying Centered Steering Wheel Position

INPUT SHAFT SEAL

Replacement

1. Park vehicle (on a level surface), turn off engine, set parking brake, chock tires, then open hood.
2. Disconnect power steering hoses from rack and pinion while using a backup wrench to prevent
rotation of fittings.
3. Remove and dispose of pinch bolt and nut from I-shaft end yoke, and disconnect end yoke from
input shaft.
4. Using screwdriver, work alignment cover off and remove dust cover.
5. Remove retaining ring using retaining ring pliers.
6. Do thorough cleaning of area to disallow contamination into gear when seal is removed.
7. Wrap input shaft and seal area with clean cloth to prevent fluid spray when seal is removed. Then
blow compressed air into outlet port and remove input shaft seal. See Fig. 7.

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Fig. 7: Input Shaft Seal

8. Install protective cap on input shaft.

9. Lubricate input shaft seal lip with some grease, Renolit JP1619N (or Mercedes-Benz DBL
6804.70), then install seal on input shaft.
10. Place depth tool over input shaft and lightly tap on tool to press seal into housing. Use rubber
mallet until tool hits upper edge of housing. Verify seal position after each tap to ensure it stays
level. Seal installation is correct when it is fully under retaining ring groove.
11. Install retaining ring using retaining ring pliers. Ensure ring is seated fully in retaining ring
groove.
12. Lubricate top of seal with grease, area must be filled completely.

NOTE: Install dust cover with outer lip upward for proper protection of
components.

13. Install dust cover, ensure outer lip of cover curves upward. Any excessive grease must be
cleaned.
14. Remove protective cap from input shaft and install alignment cover on shaft.
15. Connect steering I-shaft to steering gear input shaft with NEW pinch bolt and nut. Tighten nut to
30-35 Ft. Lbs. (41-47 N.m).
16. Lubricate exposed pinch bolt threads and nut with torque seal, OGP F900WHITE.
17. Inspect Rack And Pinion Fluid Line Fittings for a specification of 30-35 Ft. Lbs. (41-47 N.m),
and tighten them if required.
18. Connect power steering hoses to fittings, while ensuring hoses DO NOT contact axle or each
other. Ensure fittings are not turned while tightening pressure hose 43-47 Ft. Lbs. (58-64 N.m)
and return hose 55-61 Ft. Lbs. (75-83 N.m).
19. Fill and bleed power steering system, using following steps:
A. Lift front wheels off ground and put jack stands under to support vehicle.
B. While engine is off, move wheel fully left and right 5 times to bleed air from rack.
C. Add fluid to reservoir, then start engine.
D. Rotate steering wheel fully left and right repeatedly.

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E. If continued bleeding is required for steering system, do last sub-step again after fluid in
reservoir has had time to release any air.
F. Now lower vehicle after removing jack stands.

OUTER TIE ROD (LEFT SIDE)

Removal

1. Position front tires straight-ahead. Drive vehicle straight (if possible) for a short distance, and
halt at spot where servicing is to be done.
2. Turn engine OFF, set parking brakes, block tires, and then open hood.
3. Follow below procedure for replacing driver side outer tie rod.
A. Remove and dispose of cotter pin and castle nut.
B. Release jam nut and note exposed threads numbers and mark outer tie rod position for easy
installation.
C. Remove outer tie rod from tie rod arm, and unthread it from inner tie rod. If required, use a
backup wrench to hold inner tie rod for easy unthreading.

Dispose of outer tie rod.

D. Remove and dispose of jam nut.

Installation

1. Install NEW jam nut.

2. Install NEW outer tie rod and verify that position and number of exposed threads on outer tie rod
position is same as previously noted.
3. Tighten jam nut.
4. Connect rack and pinion outer tie rod to tie rod arm using a NEW castle nut, and tighten to 240
Ft. Lbs. (325 N.m). Continue tightening until alignment of next castle nut slot with ball stud hole
occurs. Insert NEW cotter pin.
5. Tighten jam nut of driver side to 285-305 Ft. Lbs. (386-413 N.m), and to passenger side, tighten
clamp nut to 30-36 Ft. Lbs. (41-48 N.m).

OUTER TIE ROD (RIGHT SIDE)

Removal

1. To replace passenger side outer tie rod, proceed as follows.

A. Remove and dispose of cotter pin and castle nut.
B. Remove outer tie rod.
C. Loosen tie rod clamp, and mark outer tie rod position and note down exposed threads
number for easy installation.
D. Unthread outer tie rod, holding inner tie rod (if required) in place, using backup wrench.

NOTE: Mark threads and/or count number of turns to remove tie rod
for NEW installation.

Dispose of outer tie rod.

Installation

1. Install NEW outer tie rod on inner tie rod, counting number of turns noted in removal.
2. Tighten tie rod clamp.
3. Connect outer tie rod of rack and pinion to tie rod arm using NEW castle nut and tighten to 240

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Ft. Lbs. (325 N.m). Continue tightening until alignment of next castle nut slot with ball stud hole
occurs. Insert NEW cotter pin.
4. Tighten jam nut of driver side to 285-305 Ft. Lbs. (386-413 N.m), and to passenger side, tighten
clamp nut to 30-36 Ft. Lbs. (41-48 N.m).

RACK & PINION

Removal

1. Put front tires in straight-ahead position. Drive vehicle in a straight line for a short distance (if
possible), stopping at spot where work is to be done.
2. Turn off engine, set parking brakes, block tires, and open hood.
3. Clean all fittings and hose connections on steering gear until all dirt is removed.
4. Disconnect fluid lines from steering gear while using a backup wrench to keep fittings still. Then
seal all openings and fittings to keep out dirt.
5. Remove cotter pins and castle nuts from outer tie rods, then disconnect them from tie-rod arms.
Dispose of castle nuts and cotter pins.
6. Disconnect end yoke of steering I-shaft from rack and pinion input shaft. Dispose of pinch bolt
and nut.
7. Remove fasteners connecting rack and pinion to axle steering gear brackets. Remove rack and
pinion and dispose of fasteners.

Installation

1. Install steering gear on axle steering gear brackets, using NEW fasteners. Tighten fasteners to
202-256 Ft. Lbs. (274-347 N.m).
2. With NEW castle nuts, connect Outer Tie-Rods of rack and pinion to tie-rod arms. Tighten nuts
to 240 Ft. Lbs. (325 N.m). Install NEW cotter pins; if required, continue to tighten until next
castle nut slot aligns with hole in ball stud and pin can be inserted.
3. Put rack travel center and align timing pointers on input shaft seal cover and input shaft housing.
See Fig. 3.
4. Connect Steering I-Shaft To Steering Gear Input Shaft using pinch bolt and nut. Tighten nut to
30-35 Ft. Lbs. (41-47 N.m).
5. Apply torque seal (OGP F900WHITE) to exposed pinch bolt threads and nut.
6. Install Fittings Into NEW Steering Gear (if required), and tighten to 30-35 Ft. Lbs. (41-47 N.m).
7. Connect hoses to fittings, ensure hoses DO NOT contact axle or each other. Hold fittings still
while Pressure Hose is tightened to 43-47 Ft. Lbs. (58-64 N.m) and Return Hose to 55-61 Ft.
Lbs. (75-83 N.m).
8. Add Dexron III or ConocoPhillips Super ATF to fill power steering reservoir.
9. Lift front axle and set jack stands to hold frame. While front wheels are off ground, bleed
steering systems using following steps.
A. While engine is off, move wheel fully left and right 5 times to bleed air from rack.
B. Add fluid to reservoir, then start engine.
C. Rotate steering wheel fully left and right repeatedly.
D. If steering system needs continued bleeding, repeat last sub-step when fluid in reservoir
has had time to release any air.
10. Lower vehicle after removing jack stands. Set toe-in.

ZF STEERING I-SHAFT

Removal

WARNING: For safe operation of vehicle, strictly follow instructions given in

this article, because steering mechanism plays a vital role in

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vehicle operation. Ignorance may cause loss of steering, leading to

personal injury or property damage.

1. With front wheels positioned straight to front, drive vehicle straight for a small distance, and halt
it at mark where service is to be performed.
2. Turn OFF engine, set parking brakes, and block wheels.
3. Open hood.
4. Remove and dispose of, steering I-shaft pinch bolt from upper end.
5. Remove and dispose of, steering I-shaft pinch bolt and nut from upper end. Remove steering I
shaft.

Installation

1. Connect steering I-shaft to input shaft of steering gear with NEW M10 x 1.25 pinch bolt and nut,
and tighten to 30-35 Ft. Lbs. (41-47 N.m).
2. Connect steering column shaft end to steering I-shaft with NEW M10 x 1.25 pinch bolt and nut,
and tighten to 30-35 Ft. Lbs. (41-47 N.m).
3. Seal exposed pinch bolt threads and nuts using OGP F900WHITE.

SPECIFICATIONS
PUMP FLOW RATES

MINIMUM MEASURED PUMP FLOW RATES

Flow at 1500 RPM, Flow at 1000 Psi Flow at 1800 Psi (12
No Load: gpm (6900 Kpa): gpm 400 Kpa): gpm
Application (L/min) (L/min) (L/min)
Sheppard HD94 3.7 (14.0) 2.6 (9.8) 1.8 (6.8)
Sheppard M100 2.8 (10.6) 2.3 (8.7)
ThyssenKrupp LZS5 3.3 (12.5) 2.8 (10.6)
Rack and Pinion
TRW TAS40 2.1 (7.9)(1) 1.6 (6.1)
TRW TAS55 2.4 (9.1)(1) 1.9 (7.2)
TRW TAS65 2.8 (10.6)(1) 2.3 (8.7)
TRW TAS65 With C28 5.8 (22.0) 4.9 (18.5) 4.4 (16.7)
or C32 Linear Cylinder
TRW TAS65 With
RCS65
TRW TAS85 3.7 (14.0) 3.3 (12.5) 2.8 (10.6)
TRW TAS85 With C28 5.8 (22.0) 5.4 (20.4)(1) 4.9 (18.5)
or C32 Linear Cylinder
TRW TAS85 With
RCS65
TRW THP45 3.7 (14.0) 2.2 (8.3) 1.4 (5.3)
TRW THP60 or PCF60 2.6 (9.8) 1.8 (6.8)
TRW THP60 With 5.8 (22.0) 4.1 (15.5) 3.3 (12.5)
Linear Cylinder
TRW THP60 With
RCH45
(1) Approximate value based on flow at 1800 Psi (12 400 Kpa).

STEERING GEAR RELIEF PRESSURES

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TYPICAL STEERING GEAR RELIEF PRESSURE AT ENGINE IDLE

Application Psi (kPa)
Sheppard HD94 2683 ± 100 (18 500 ± 700)
Sheppard M100 2175 ± 100 (15 000 ± 700)
ThyssenKrupp LZS5 Rack and Pinion 2300 ± 116 (15 500 ± 800)
TRW TAS40 2175 ± 100 (15 000 ± 700)(1)
TRW TAS55
TRW TAS65
TRW TAS85
TRW TAS65 With C28 or C32 Linear Cylinder
TRW TAS65 With RCS65
TRW TAS85 With C28 or C32 Linear Cylinder
TRW TAS85 With RCS65
TRW THP45 2683 ± 100 (18 500 ± 700)
TRW THP60 or PCF60
TRW THP60 With Linear Cylinder
TRW THP60 With RCH45
(1) On vehicles equipped with TRW TAS steering gears and hydraulic brakes, typical relief
pressure is 2375 ± 100 Psi (16 375 ± 690 Kpa).

TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
Application Ft. Lbs. (N.m)
3/4-16 Castle Nuts 90-170 (122-230)
7/8-14 Castle Nuts 160-300 (217-407)
Axle Steering Gear Brackets 202-256 (274-347)
Clamp Nut 30-36 (41-48)
Fittings Into NEW Steering Gear 30-35 (41-47)
Pressure Hose Fitting 43-47 58-64)
Rack & Pinion Fluid Line Fittings 30-35 (41-47)
Return Hose Fitting 55-61 (75-83)
Steering Wheel Nut 33-41 (45-55)
Steering I-Shaft To Steering Gear Input Shaft 30-35 (41-47)
Tie Rod Castle Nuts 240 (325)
Tie Rod Clamp Nut 30-36 (41-48)
Tie Rod Jam Nut 285-305 (386-413)

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