Knuckle/Spindle - Rear

This procedure covers the removal and replacement of the rear spindle/knuckle assembly on a 2007 Ram 3500 4WD with 5.9L Cummins diesel, including bearing and seal service.

Warnings

Tools required

Parts

• Rear spindle/knuckle assembly × 1 — Use OEM specification
• Rear wheel bearing set (inner and outer) × 1 — Use OEM specification
• Rear axle seal × 1 — Use OEM specification
• Spindle nut × 1 — Use OEM specification
• Cotter pin × 1 — Use OEM specification
• Brake hardware kit × 1 — Optional, includes clips and springs

Fluids

• 75W-90 synthetic gear oil — 6 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock front wheels securely
3. Loosen rear wheel lug nuts while vehicle is on ground
4. Raise rear of vehicle and support with rated jack stands under frame rails
5. Remove rear wheel and tire assembly
6. Place drain pan under rear differential to catch gear oil
7. Clean spindle and hub area with brake cleaner to remove road debris

Procedure

1. 1

   Remove brake caliper and rotor
   Remove brake caliper mounting bolts and hang caliper safely from frame or suspension using wire hangers. Do not allow caliper to hang by brake hose. Remove the brake rotor. On this full-floating axle the rotor may be captured by the hub assembly — verify whether the rotor slides off independently or must be removed with the hub per the service manual. If rotor is stuck, use penetrating oil and tap lightly with brass hammer.
2. 2

   Remove axle shaft
   Remove the eight axle flange retaining bolts securing the axle shaft flange to the hub. Pull the axle shaft straight out of the axle tube and set aside. On this full-floating axle the shaft is isolated from differential fluid, so minimal or no fluid will drain from the tube. Inspect axle shaft splines and flange for wear or damage.
3. 3

   Remove spindle hardware
   Remove and discard the cotter pin from the spindle nut. Using a large adjustable wrench or spindle nut socket, remove the spindle nut. Remove the outer nut washer. Keep track of washer orientation for reassembly.
4. 4

   Remove hub and spindle assembly
   Carefully pull the hub assembly straight off the spindle. The outer bearing and seal will come off with the hub. Set hub aside on clean surface. Remove the four bolts securing the spindle to the brake backing plate and axle housing flange. Remove spindle from vehicle. Inspect spindle for cracks, excessive wear, or damage to bearing surfaces.
5. 5

   Remove and inspect old bearings and seals
   Using a brass drift or bearing race driver, drive out the inner and outer bearing races from the hub. Work evenly around the race to prevent cocking. Remove and discard the inner axle seal from the hub. Clean hub thoroughly with brake cleaner and inspect bearing bores for scoring, pitting, or damage. Replace hub if bearing bores are damaged.
6. 6

   Install new bearing races
   Position new outer bearing race squarely in hub bore. Using appropriate bearing race driver, drive race into hub until fully seated. Race should be flush and fully seated around entire circumference. Repeat for inner bearing race. Verify both races are fully seated and not cocked in bores.
7. 7

   Pack and install new bearings
   Pack inner and outer wheel bearings with high-temperature wheel bearing grease using bearing packer or by hand. Work grease completely through bearing until grease appears on opposite side. Apply thin coating of grease to bearing races in hub. Install packed inner bearing into inner race. Install new inner axle seal using seal driver, driving seal in until flush with hub face.
8. 8

   Install spindle assembly
   If replacing spindle, transfer any brackets or hardware from old spindle to new unit. Clean spindle mounting surface on axle housing and backing plate. Position spindle onto brake backing plate and axle housing flange. Install the mounting bolts and tighten in a cross pattern to the manufacturer's specified torque (verify count and torque value against factory service manual for the AAM 11.5 axle before assembly).
9. 9

   Install hub assembly
   Apply thin coat of wheel bearing grease to spindle bearing surfaces. Carefully slide hub assembly with inner bearing and seal onto spindle. Ensure seal does not cock or bind during installation. Hub should slide on smoothly without excessive force.
10. 10

    Install outer bearing and adjust
    Install packed outer bearing into hub outer race. Install outer bearing washer over spindle with chamfered edge toward bearing. Adjust wheel bearings following the factory AAM 11.5 procedure: torque the inner adjusting nut to the specified value while rotating the hub to seat the bearings, back off as specified, retorque to final spec, then install the keyed lock washer and outer locknut per the service manual. Verify the specific adjustment torques and locking hardware (this axle typically does not use a cotter pin) before assembly. ends to secure.
11. 11

    Reinstall axle shaft
    Clean axle shaft splines and apply thin coat of gear oil to shaft. Carefully align axle shaft splines with differential side gear and slide shaft into axle housing until flange contacts hub. Install the eight axle flange bolts and tighten in a star pattern to the factory-specified torque (verify against the service manual for the AAM 11.5 axle before assembly).
12. 12

    Reinstall brake components
    Clean rotor mounting surface on hub and rotor hat with brake cleaner. Install brake rotor onto hub, ensuring it seats fully. Reinstall brake caliper and tighten mounting bolts to the factory-specified torque (verify against the service manual; caliper bracket bolts are typically around 130-160 ft-lbs and guide/slide pin bolts around 25-40 ft-lbs — do not exceed these).
13. 13

    Refill differential and reinstall wheel
    Only refill the rear differential if fluid was actually lost. If refill is needed, add 75W-90 synthetic gear oil through the fill plug opening until fluid reaches the bottom of the fill hole (AAM 11.5 capacity is approximately 3.5 quarts — verify against service manual). Install fill plug. Install wheel and tire assembly. Hand-tighten lug nuts in star pattern. Lower vehicle to ground and torque lug nuts to specification (typically 135-145 ft-lbs for 3500 series) in star pattern.

Reassembly

1. Torque all fasteners to specification using proper sequence
2. Verify spindle nut is properly adjusted with minimal end play
3. Ensure cotter pin is properly installed and secured
4. Check that brake caliper is properly mounted and brake hose is not twisted or kinked
5. Verify differential is filled to proper level
6. Double-check all brake line connections are secure

Verification

• Pump brake pedal several times to restore proper brake pad position and verify firm pedal feel
• Check for any gear oil leaks around axle seal and differential
• Rotate wheel by hand to verify smooth operation without binding or grinding
• Check for excessive wheel bearing end play by attempting to rock wheel top-to-bottom
• Test drive vehicle in safe area at low speed to verify proper brake operation and no unusual noises from rear axle
• Perform several moderate brake applications and verify straight stopping with no pulling
• After initial test drive, recheck wheel lug nut torque and spindle nut cotter pin security
• Inspect for any fluid leaks after test drive

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