Steering Knuckle and King Pin Replacement Without -FH4

Tools Required

1. Set the parking brake.
2. Block the vehicle rear wheels.
3. Raise the front of the vehicle until the tires clear the floor.
4. Support the frame using suitable safety stands.
5. Remove the front wheels. Refer to Front Wheel Hub, Bearing, and Seal Replacement .
6. Remove the brake components as needed. Refer to Front Brake Caliper Replacement in Disc Brakes.
7. Remove the brake backing plates and the dust covers.



8. Remove the tie rod arm bolts (9). Lower the tie rod arm (10) and the tie rod to the floor.
9. Remove the steering arm bolts (5). Support the steering arm (6) and the steering rod out of the way.
10. Remove the king pin upper cap (1).
11. Remove the following components:

•	The bolts (17)

•	The washers (18)

•	The king pin lower cap (15)

•	The gasket (14)

12. Remove the king pin nut (2).



13. Using J 39758 , insert the tool pins into the holes at the bottom of the king pin. Align the tools bolt holes and secure with 2 bolts into the steering knuckle. This prevents the king pin from spinning.



14. Remove the king pin (12) by knocking out the pin with a soft-faced mallet.
15. Remove the steering knuckle (20).
16. Remove the following components from the knuckle (20):

•	The seals (19)

•	The bearing (3)

•	The shim or spacer (4)

•	The bushing (13)

17. Remove the king pin bushing (13), if required. Refer to King Pin Bushing and Bearing Cup Replacement .

1. Clean the axle components using a cleaning solvent.
2. Soak the thrust bearing until all of the old lubricant is gone.
3. Inspect the axle components for the following conditions:

•

Wear

•

Pitting

•

Cracks

•

Damage

4. Use Magna-Flux™ inspection, if available, in order to inspect the steering knuckle (20) and the kingpins (12) for minute cracks, checks, or fractures.
5. Inspect the thrust bearings and the cups for rough rotation.
6. Inspect the axle king pin (12) bores for the following conditions:

•

Scratches

•

Burrs

•

Corrosion

7. Inspect the king pin bushing (13) bores for the following conditions:

•

Scratches

•

Burrs

•

Corrosion

8. Smooth the bore using a crocus cloth or a fine grit sandpaper if needed. Clean the bore.

1. Install the king pin bushings (13), if removed.
2. Install the king pin bearing cup, if removed.
3. Install the steering knuckle (20).
4. Install the king pin (12). Install the dust seals (19).
5. Install a shim or spacer (4).
6. Install the king pin thrust bearing (3). Pack the bearing thoroughly with high temperature wheel bearing grease.
7. Install the king pin nut (2).



8. Using J 39758 insert the tool pins into the holes at the bottom of the king pin.
9. Align the tool's bolt holes.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

10. Secure the tool with 2 bolts into the steering knuckle in order to keep the king pin from spinning.

Tighten
Tighten the nut to 550 N·m (406 lb ft).




11. Measure the king pin bearing preload. Refer to King Pin Bearing Preload .



12. Install the following components:

•	The bottom gasket (14)

•	The dust cap (15)

•	The flat washers (18)

•	The bolts (17)

Tighten
Tighten the dust cap bolt to 24 N·m (18 lb ft).

13. Install the king pin upper dust cap (1). Tap into place with a soft-faced mallet. Grease the knuckle (19) through the lubrication fitting (16) on the bottom.
14. Install the tie rod arm (10).
15. Install the steering arm (6), if removed.
16. Install the brake backing plate and the dust cover.
17. Install the brake components as needed. Refer to Front Brake Caliper Replacement in Disc Brakes.
18. Install the front wheels. Refer to Front Wheel Hub, Bearing, and Seal Replacement .
19. Remove the safety stands and lower the vehicle.
20. Check the axle alignment.
21. Check the stop screw (7, 8) adjustment. Adjust as needed. Refer to Stop Screw Adjustment in Wheel Alignment.

Steering Knuckle and King Pin Replacement With FH4

Tools Required

J 8001 Dial Indicator Set

1. Prior to performing inspections, the following preliminary steps should be accomplished.

1.1.	Set the parking brake.

1.2.	Block the vehicle rear wheels.

1.3.	Raise the front of the vehicle until the tires clear the floor.

1.4.	Support the frame using suitable safety stands.

Important:  Inspection procedures assumes axle is assembled and installed in vehicle with tire and wheels. Checking knuckle vertical play during axle assemble requires different procedure.




2. Mount dial indicator (1) on axle beam (3). Reference the knuckle cap.



3. Pry steering knuckle downward (2).
4. Zero the dial indicator (1).
5. Lower the front axle (3) to obtain the indicator reading. If reading exceeds 1.02 mm (0.040 in) , inspect thrust bearings. Replace if necessary and adjust.

1. Mount a dial indicator (3) on the axle (2) as shown. Reference upper part of knuckle.
2. Move top of wheel in and out with a push/pull motion. Have assistant monitor the dial indicator.
3. Readings in excess of 0.015 in (0.38 mm) indicate the need for bushing replacement.

1. Mount dial indicator (2) on the axle (3). Reference the lower Ackermann Arm socket of the steering knuckle (1).
2. Move bottom of wheel in and out with a push/pull motion. Have assistant read dial indicator.
3. Dial indicator readings in excess of 0.015 in (0.38 mm) indicate that the lower bushing should be replaced.

1. Set the parking brake.
2. Block the vehicle rear wheels.
3. Raise the front of the vehicle until the tires clear the floor.
4. Support the frame using suitable safety stands.
5. Remove the following components as needed. Refer to Brake Drum Replacement in Air Drums.

•	The wheels

•

The hubs

•	The bearings

6. Remove the brake components as needed. Refer to Brake Drum Replacement in Air Drums.
7. Remove the cotter pin from the tie rod ball joint.



8. Remove the nut (5) from the drag link steering arm.
9. Disconnect the drag link from the steering arm.

Important: Do not use heat on any parts or fasteners.

10. Remove the following components:

•	The cap screws (9)

•	The lockwashers (10)

•	The upper and lower knuckle caps (11)

•	Remove nut (16) from the draw key (3).

11. Remove the draw key (3) from axle using a hammer and a brass drift.
12. Remove the knuckle pin (13) by knocking out with a hammer and a brass drift.
13. Remove the steering knuckle (14).
14. Remove the following components from the knuckle:

•	The seals (1)

•	The thrust bearing (4)

•	The shims (2)

15. Remove the king pin bushings (12) using a piloted drift tool.
16. Discard the thrust bearing (4).

1. Clean the axle components using a cleaning solvent.



2. Inspect the axle components for the following conditions:

•

Wear

•

Pitting

•

Cracks

•

Damage

3. Use Magna-Flux™ inspection, if available, in order to inspect the steering knuckle (14) and the kingpins (13) for minute cracks, checks, or fractures.
4. Inspect the axle king pin (13) bores for the following conditions:

•

Scratches

•

Burrs

•

Corrosion

5. Inspect the king pin bushing bores for the following conditions:

•

Scratches

•

Burrs

•

Corrosion

6. Smooth the bore using a crocus cloth or a fine grit sandpaper if needed. Clean the bore.

1. Install the king pin bushings (2) noting the bushing position (1).






Important: When installing grease seal, be sure lip (1) is pointing toward center of knuckle.

2. Install new grease seals.



3. Lightly lubricate (1) the following components:

•	The thrust bearing areas of the steering knuckle

•	The axle end

•	The knuckle pin bore of the axle beam

•	Pack the bushing bores with grease.




4. Position the thrust bearing (4) on the knuckle (14).
5. Install the knuckle (14) to the axle beam.
6. Install shims (2) at knuckle (14) upper end to remove vertical end play.
7. Install pin (13) in knuckle (14) and axle from the top.
8. Align the flat of the knuckle pin (13) with the draw key hole.
9. Install shims (2) at knuckle upper end to remove vertical end play.
10. Check knuckle vertical play and adjust.



11. Check knuckle vertical play using a dial indicator. Reference dial indicator at top of knuckle pin.



12. Simulate axle loading with a jack and note dial indicator reading.

Measure
Knuckle vertical play should be 0.015-0.305 mm (0.002-0.012 in).

13. Add or remove shims as necessary to obtain correct vertical end play.



14. Install a new draw key.
15. Align the draw key hole with the knuckle pin flat.




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

16. Install draw key nut (16).

Tighten
Tighten the nut to 50 N·m (37 lb ft).

Important: Do not apply excessive silicone compound which could block the grease path for the knuckle pin bushings.

17. Apply silicone rubber gasket compound to knuckle (14) cap mounting surface.
18. Install the knuckle king pin caps (11).
19. Install the lockwashers (10).
20. Install the cap screws (9).

Tighten
Tighten the screws to 35 N·m (26 lb ft).

21. Install the drag link to the steering arm.
22. Install the drag link ball joint nut (5).

Tighten
Tighten the nut to 270 N·m (200 lb ft).

23. Install the cotter pin (6).



24. Install the tie rod ball joint (7) to the Ackermann arm (8).

Important: Tighten the nut to the specified torque, than tighten to align cotter pin hole.

25. Install the tie rod ball joint nut (1).

Tighten
Tighten the nut to 268 N·m (198 lb ft).

26. Install the cotter pin (2).
27. Install brake components. Refer to Brake Drum Replacement in Air Drums.

•	The wheel bearings

•

The hubs

•	The wheels

28. Remove the safety stands and lower the vehicle.
29. Check the axle alignment.
30. Check the stop screw adjustment. Adjust as needed.

Stop Screw Adjustment
Adjust the steering stops so that the power assist stops approximately 3 degrees or 3.175 mm (1/8 in) before reaching the steering stop screws.