when performing the tightening procedure.
6. Secure the leaf spring and clamp group
assembly in a suitable holding device, such
as a soft jaw vise, see Figure 9-12.

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1" Hex Bolt

33

Vice

Leaf Spring and Clamp Group Assembly

Component Replacement

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
FIGURE 9-13

7. Ensure that the clamp group is properly aligned and the top pad is centered on the leaf spring.
8. Tighten the clamp assembly hex bolts evenly in 100 foot pounds increments to
600 ± 20 foot pounds torque in the proper pattern to
achieve uniform bolt tension, see Figure 9‑13.
9. Install the new axle seat liner under the axle seat (liner tabs snap to the
sides of axle seat), see Figure 9-9.
THE WEIGHT OF THE LEAF SPRING AND CLAMP GROUP ASSEMBLY IS APPROXIMATELY 230 POUNDS.
CARE SHOULD BE TAKEN AT REMOVAL AND INSTALLATION TO PREVENT PERSONAL INJURY OR DAMAGE
TO COMPONENTS.

10. Install the new leaf spring and clamp group assembly (approximate weight 230 pounds) on
the axle per the Leaf Spring and Clamp Group Assembly instructions in this section.

STEERTEK NXT HIGH CAPACITY AXLE
AXLE REMOVAL
1. Place the vehicle on level floor.
2. Chock the wheels.
DO NOT USE A TORCH ON AXLE COLLAR BOLTS OR ANY OTHER PART OF THE STEERTEK NXT HIGHER
CAPACITY STEER AXLE SYSTEM. THE USE OF A TORCH CAN CAUSE DAMAGE TO CERTAIN STEERTEK NXT
COMPONENTS THAT CAN RESULT IN THE LOSS OF VEHICLE CONTROL AND POSSIBLE PERSONAL
INJURY OR PROPERTY DAMAGE.

3. Raise the frame.
FIGURE 9-14

Leaf Spring and
Clamp Group Assembly
Axle Collar Bolts
Tightening Torque
800 ± 20 ft. lbs.

Axle Wrap Liner
Holes

Axle Collar
Front, Non Threaded

Place a floor jack in center of axle
Axle Collar
Rear,Threaded

Component Replacement

34

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STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
4. Support the vehicle with frame stands and suspend the front axle with the shocks attached.
5. Remove the front wheels, hubs, brake shoes, ABS sensors, and backing plate assembly.
6. Disconnect the drag link from the steering arm.
7. Support the axle with a suitable jack.
DO NOT REPAIR OR RECONDITION SUSPENSION OR AXLE COMPONENTS FOUND TO BE DAMAGED
OR OUT OF SPECIFICATIONS. ALL SUCH DAMAGED OR OUT OF SPECIFICATION COMPONENTS MUST
BE REPLACED. ALL MAJOR HENDRICKSON COMPONENTS ARE HEAT TREATED AND TEMPERED.
STEERTEK NXT COMPONENTS CANNOT BE BENT, WELDED, HEATED, OR REPAIRED WITHOUT REDUCING
THE STRENGTH OR LIFE OF THE COMPONENT. FAILURE TO FOLLOW THESE GUIDELINES CAN CAUSE
LOSS OF VEHICLE CONTROL, AND POSSIBLE PERSONAL INJURY OR DEATH OR PROPERTY DAMAGE
AND WILL VOID APPLICABLE WARRANTIES.

8. Remove the 1" axle collar bolts and clamps, refer Leaf Spring and Clamp Group Disassembly.
9. Lower the axle and remove from the vehicle.

AXLE INSTALLATION
1. Place the new axle on the floor jack and position the axle under the vehicle, see Figure 9-14.
2. Install the new axle seat liner under the axle seat (liner ear snap to the side of the axle seat).
3. Raise the axle into position.
4. Ensure the axle seat liner holes are lined up with the axle seat and axle holes, see Figure 9-14.
5. Install the new axle collar fasteners with the bolt head located on the front side of the axle.
6. Tighten both sides, left and right of the axle collar bolts in four stages, stage one 100 foot
pounds, stage two 350 foot pounds, stage three 700 foot pounds and the fourth and final
800 ± 20 foot pounds torque, see Figure 9-15.
7. Install the steering knuckles, refer to the Steering Knuckle Assembly instructions in this ­section.
FIGURE 9-15

8. Install the tie rod assembly into the tie rod
arms.
9. Install the 7⁄8" washers on the tie rod arms
and the castle nuts. Tighten the castle
nuts to 185 foot pounds, then rotate
until the first castle slot lines up with the
cotter pin bore in the tie rod end. DO NOT
back off nut for cotter pin installation.
10. Install the tie rod end cotter pin.
11. Connect the drag link in the steering arm.
12. Install the castle nut on the drag link taper
stud. Tighten the c­ astle nut to 185 foot
pounds, then rotate until the first castle
slot lines up with the cotter pin bore in the
drag link. DO NOT back off nut for cotter
pin installation.

1" Clamp Group Hex Bolt
Tightening Torque at
the Bolt Head
600 ± 20 ft. lbs.
IMPORTANT
Ensure that Clamp
Group Assembly
is properly aligned

1" Axle Collar Bolt
Tightening Torque
800 ± 20 ft. lbs.

13. Install the drag link cotter pin.
14. Install the brake backing plate assemblies and ABS sensor and torque all fasteners per manufacturer’s specifications.
15. Install the brakes, hubs, and wheels per the vehicle manufacturer’s guidelines.
16. Raise the vehicle and remove the frame supports.
17. Lower the vehicle and load the front axle with the truck’s weight. Remove the floor jack.

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35

Component Replacement

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
18. Remove the wheel chocks.
19. Fill the hubs with the proper lubricant, (see manufacturer’s guidelines for recommended
lubrication), if required.
20. Grease the front steering components as per lubrication guidelines in the Preventive
Maintenance Section of this publication.

STEERING KNUCKLE
STEERING KNUCKLE DISASSEMBLY

FIGURE 9-16

1. Place the vehicle on level floor.
2. Chock the wheels.
3. Support the vehicle with jack stands on the axle.
4. Remove the wheel and hub assembly.
5. Remove the brake components from steering knuckle
per the brake manufacturer’s procedure.
SERVICE HINT

Lightly tap the side
of tie rod arm to
loosen the tie rod end

Lightly tap the side of the tie rod arm with a mallet to
separate the tie rod end from the tie rod arm, see
Figure 9-16.

6. Disconnect the tie rod assembly from the tie rod arms, see Figure 9-16.
7. Remove the tie rod assembly.

STEERING ARM DISASSEMBLY
1. Remove the two steering-arm-toknuckle hex bolts from the knuckle
assembly. Figure 9-17.

FIGURE 9-17
Knuckle Assembly
1" Hex Bolt

2. Remove the steering arm from the
knuckle. If necessary, use a leather or
plastic mallet to tap the outside of the
arm and separate the arm from the
knuckle.

Steering Arm

3. Remove the steering arm.
4. Inspect the steering arm for cracks or damage, replace as necessary.

TIE ROD ARM DISASSEMBLY
SUPPORT THE TIE ROD ASSEMBLY DURING
MAINTENANCE AND SERVICE TO PREVENT
SERIOUS PERSONAL INJURY AND DAMAGE TO
COMPONENTS.

FIGURE 9-18
Knuckle
Assembly

Castle Nut
Cotter Pin

DO NOT HEAT THE ARM TO REMOVE THE TIE ROD
ASSEMBLY. HEATING THE TIE ROD ARM WILL
SOFTEN PARTS. DAMAGE TO COMPONENTS WILL
RESULT.

Component Replacement

Tie Rod End

1. Remove tie rod arm 7⁄ 8 " fasteners and
discard.

Tie Rod Arm

2. Remove the tie rod arms, see Figure 9-18.

7 8

36

/ " Hex Bolt

17730-297

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
GREASE CAP, DRAW KEY AND KINGPIN DISASSEMBLY
YOU WILL NEED:
■■

Brass drift and hammer

■■

Heavy-duty King Pin Press that can generate 46,000 Lbs of force and will accommodate
kingpins size of 2" to 25⁄32"

FIGURE 9-19

1. Remove the top grease cap.
2. Remove the draw keys.

Loosen the draw key
locknut until the top of
the locknut is even with
the end of the draw key

a. Loosen the threaded draw key locknut until the top of the locknut is
even with the end of the draw key,
see Figure 9-19.
b. Use a brass drift and a hammer to hit
the end of the draw key.

c. Remove the nut from the draw key. Remove the draw key from the knuckle.
3. If you are not replacing the bushings, use the following procedure to prevent damaging the
bushings during kingpin removal.
a. Use a brass drift and a hammer to remove the kingpins from the knuckle. Figure 9-20.
b. Remove any flaring on the drift that touches the bushings.
c. Wrap tape to a thickness of 1⁄16" (1.5 mm) onto the end of the drift.
4. If the kingpin is hard to remove, use a hydraulic kingpin remover, refer to the Special Tools
Section of this publication.
5. Remove the knuckle from the axle beam.
WEAR GLOVES WHEN YOU REMOVE OR INSTALL SHIMS. SHIMS HAVE SHARP EDGES THAT CAN CAUSE
SERIOUS PERSONAL INJURY.

6. While wearing gloves, remove the shims, the thrust bearing and the seal from the beam
and / or steering knuckle. Figure 9-21.
7. Inspect the parts, refer to the Preventive Maintenance Section of this publication.
FIGURE 9-20

FIGURE 9-21
Kingpin
Seal

Knuckle
Assembly

Kingpin
Shim
Axle Beam

Kingpin

17730-297

Kingpin
Seal

37

Thrust
Bearing

Component Replacement

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
KINGPIN BUSHING
YOU WILL NEED:
■■

Impact wrench

■■

Adjustable Straight Flute Reamer with a cutting diameter a range of 2.0" to 2.01"

Refer to the Special Tools Section of this publication for the following shop made tools:
■■

Kingpin Bushing Driver

■■

Kingpin Bushing Installer / Remover Tool

REMOVAL
1. Place the steering knuckle on a workbench squarely supported.
2. Place the STEERTEK NXT kingpin bushing Installer / Remover tool in the steering knuckle / kingpin bore, see Figure 9-22.
3. Use a hammer and drive out the kingpin bushing, see Figure 9-23.
4. Rotate the knuckle over and repeat Steps 1-3 to remove the other kingpin bushing.
5. Clean the knuckle kingpin bores with a rotary wire wheel and inspect for reassembly, see
Figure 9-24.
FIGURE 9-22

Component Replacement

FIGURE 9-23

FIGURE 9-24

38

17730-297

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
STEERING KNUCKLE BORE MEASUREMENT
Complete the following steering knuckle bore inspection and the measurement instructions prior
to installing the kingpin bushing.
1. Measure the upper knuckle bore inside diameter at two locations. Always use an inside
micrometer or a telescoping gauge when taking a knuckle bore measurement. Some outof-roundness at the top and bottom of the bore edges is acceptable. Steering knuckle bore
diameter is 1.938" ± 0.003".
2. Measure the upper and lower bore in two positions and at two locations. The two positions
must be 90º opposed from each other, see Figures 9-25 through 9-27. If the average measurement is more than the knuckle bore maximum diameter specification, replace the knuckle.
FIGURE 9-25

FIGURE 9-26

FIGURE 9-27

INSTALLATION
1. Install kingpin bushings from the axle side of the steering knuckle.
2. Place the new kingpin bushing into the steering knuckle bore so the seam DOES NOT align
with the grease channel, see Figures 9-28 and 9-29.
3. Use the kingpin bushing driver to install the kingpin bushing into the steering knuckle bore,
see Figure 9-30. Continue installation until the kingpin bushing is flush with the machined
surface of the steering knuckle.
FIGURE 9-28

FIGURE 9-29
NOTE the
location of the
grease channel

17730-297

39

DO NOT place the Kingpin INCORRECT Kingpin
Bushing Seam in line bushing orientation
with the grease channel

Component Replacement

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
FIGURE 9-30

FIGURE 9-31

FIGURE 9-32

4. Remove the kingpin bushing driver.
5. Install the kingpin bushing installer / remover tool.
6. Continue driving the kingpin bushing into the steering knuckle until it is flush with the bottom
of kingpin seal bore, see Figures 9-31 and 9-32.
7. Repeat steps for the remaining kingpin bushing.
8. Ream the bushings, see Reaming procedure in this section.

KINGPIN PREPARATION AND MEASUREMENT
Cleaning Ground and Polished Parts
■■

Use a cleaning solvent to clean ground or polished parts and surfaces. DO NOT USE
GASOLINE.

■■

DO NOT clean ground or polished parts in a hot solution tank or with water, steam, or alkaline
solutions. These solutions will cause corrosion of the parts.

Drying the Cleaned Parts
■■

Parts must be dried immediately after cleaning. Dry the parts with clean paper towels, clean
rags, or compressed air. DO NOT dry bearings by spinning with compressed air. Damage to
the bearings will result.

Preventing Corrosion on Cleaned Parts
■■

Apply a light coating of oil to all cleaned and dried parts that are going to be reused. DO NOT
apply oil to the brake lining or the brake drums. If parts are to be stored, apply an effective rust
inhibitor to all surfaces.

TO HELP PREVENT SERIOUS EYE INJURY, ALWAYS WEAR PROPER EYE PROTECTION WHEN YOU
PERFORM VEHICLE MAINTENANCE OR SERVICE.
SOLVENT CLEANERS CAN BE FLAMMABLE, POISONOUS AND CAUSE BURNS. TO HELP AVOID SERIOUS
PERSONAL INJURY, CAREFULLY FOLLOW THE MANUFACTURER’S PRODUCT INSTRUCTIONS AND
GUIDELINES AND THE FOLLOWING PROCEDURES:
■■
■■
■■

Component Replacement

WEAR PROPER EYE PROTECTION.
WEAR CLOTHING THAT PROTECTS YOUR SKIN.
WORK IN A WELL VENTILATED AREA.
40

17730-297

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
■■

■■

DO NOT USE GASOLINE, SOLVENTS OR OTHER MATERIALS THAT CONTAIN GASOLINE THAT CAN
EXPLODE.
HOT SOLUTION TANKS OR ALKALINE SOLUTIONS MUST BE USED CORRECTLY. FOLLOW THE
MANUFACTURER’S RECOMMENDED INSTRUCTIONS AND GUIDELINES CAREFULLY TO HELP
PREVENT PERSONAL ACCIDENT OR INJURY.

DO NOT USE HOT SOLUTION TANKS OR WATER AND ALKALINE SOLUTIONS TO CLEAN GROUND OR
POLISHED PARTS. DAMAGE TO THE PARTS WILL RESULT.

1. Inspect the kingpin for wear or damage. Use a micrometer and measure the kingpin. If the
kingpin has less than 2.0" diameter, replacement is necessary, see Figure 9-33.
2. Set up the reamer to match kingpin dimension, see Figure 9-34. The dimension of cutting
diameter must facilitate a range of 2.0" to 2.001".
Kingpin minimum dimension is 2.0"
FIGURE 9-33

FIGURE 9-34

Kingpin minimum
dimension is 2.0"

The cutting diameter
dimension must facilitate
a range of 2.0" to 2.001"

KINGPIN BUSHING REAMING
YOU WILL NEED:
■■

Fixed Reaming Tool, refer to Special Tools Section of this publication.

REAM THE KINGPIN BUSHINGS WITH AN ADJUSTABLE STRAIGHT FLUTE REAMER. (SEE SPECIAL TOOLS
SECTION OF THIS PUBLICATION) DO NOT HONE OR BURNISH THE KINGPIN BUSHINGS. HONING OR
BURNISHING WILL DAMAGE THE BUSHINGS AND VOID ANY APPLICABLE WARRANTY.
WHEN INSTALLING STEERING KNUCKLE COMPONENTS IN A VISE IT IS NECESSARY TO PROTECT THE
MACHINED SURFACES FROM GOUGES OR MARRING BY USING BRASS JAWS. FAILURE TO DO SO CAN
CAUSE PREMATURE PART DAMAGE, DAMAGE TO THE STEERING KNUCKLE COMPONENTS, LOSS OF
WARRANTY, LOSS OF VEHICLE CONTROL, CAUSING PERSONAL INJURY OR PROPERTY DAMAGE.
PRIOR TO INSTALLATION ENSURE THAT ALL RESIDUAL LOCTITE® MATERIAL IS REMOVED FROM THE
MOUNTING BOLTS AND THE THREAD BORES IN THE UPPER STEERING KNUCKLES, AND NEW LOCTITE
277 OR EQUIVALENT IS APPLIED TO HELP ENSURE THAT THE BOLTS SUSTAIN THE PROPER TORQUE
REQUIREMENT. FAILURE TO DO SO CAN CAUSE LOSS OF VEHICLE CONTROL RESULTING IN PERSONAL
INJURY OR PROPERTY DAMAGE.

NOTE

17730-297

Bushing size is to be 0.001" larger than the kingpin size.

41

Component Replacement

STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles
FIGURE 9-35

USE A FIXED REAMER TO REAM THE
KINGPIN BUSHINGS. DO NOT HONE OR
BURNISH THE BUSHINGS. DAMAGE TO
THE BUSHINGS WILL RESULT.

1. Place the knuckle in a vise with
brass jaws, see Figure 9-35.
2. Install the pilot in the lower kingpin
bore.
3. Install the reamer into the pilot.
4. Slide the reamer into the upper
bushing and into the pilot until the reamer blades touch the bushing.
5. Rotate the reamer with a light DOWNWARD pressure. DO NOT apply too much force. Rotate
the reamer smoothly, see Figure 9-36.
6. Turn the knuckle over in the vise and repeat Steps 2-5 for the other kingpin bushing. Figures
9-36 and 9-37.
SERVICE HINT

If the reamer must be removed through the bushing. Rotate the tool in the opposite cutting
direction.
7. Clean all material from the bushings.
8. Lightly lubricate the new the kingpin with penetrating oil and slide into the steering knuckle
bore to ensure the kingpin fits properly into the kingpin bushings.
FIGURE 9-36

Component Replacement

FIGURE 9-37

42

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STEERTEK NXT High Capacity Steer Axle System for Autocar® ACX-XPEDITOR™ Vehicles