Lateral Arm

Replacement of the front lateral arm (upper or lower control arm) on a 4WD Dodge Ram 2500 with 5.9L Cummins diesel engine.

Warnings

Tools required

Parts

• Upper or lower control arm assembly × 1 — Use OEM specification or Moog K7397 (upper) / K7207 (lower)
• Cotter pin × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and set parking brake
2. Chock rear wheels securely
3. Loosen front wheel lug nuts while vehicle is on ground
4. Raise front of vehicle with floor jack at frame rail
5. Support vehicle on jack stands placed at manufacturer-specified points on frame
6. Remove front wheel and tire assembly
7. Apply penetrating oil to ball joint nut, control arm bolts, and any rusted fasteners. Allow to soak 15-20 minutes

Procedure

1. 1

   Support the knuckle assembly
   Place a floor jack under the lower control arm or knuckle assembly to support the weight of the suspension components. This prevents the assembly from dropping when the ball joint is disconnected and maintains alignment for reassembly.
2. 2

   Remove sway bar link if necessary
   If replacing the lower control arm, disconnect the sway bar end link from the control arm. Remove the cotter pin and nut. You may need to hold the stud with an Allen key while removing the nut. If replacing upper control arm, skip this step.
   Torque spec

   Sway Bar Link61 Nm (45 lb-ft)
3. 3

   Remove ball joint cotter pin and nut
   Straighten and remove the cotter pin from the ball joint castle nut using pliers or a cotter pin removal tool. Remove the ball joint castle nut completely. Note the orientation and number of threads showing for reference during reassembly.
4. 4

   Separate ball joint from knuckle
   Use a ball joint separator tool or pickle fork to separate the ball joint taper from the steering knuckle. Insert the separator between the control arm and knuckle, then strike with a hammer or tighten the separator tool. The joint should pop free with a loud crack. Do not pry against rubber boots.
   ⚠Pickle fork tools will damage ball joint boots. Use a proper ball joint separator if reusing components.
5. 5

   Remove shock absorber mounting if necessary
   If the shock absorber interferes with removal, disconnect the lower shock bolt from its mount. You may only need to loosen the bolt to provide clearance rather than complete removal.
   Torque spec

   Strut Bolts115 Nm (85 lb-ft)
6. 6

   Remove control arm frame mounting bolts
   Locate the control arm mounting bolts at the frame. There are typically two bolts: one at the front bushing and one at the rear bushing. Use a breaker bar to loosen these bolts, then remove them completely. Note the orientation of any washers, sleeves, or spacers for correct reassembly.
   ⚠Control arm may be under tension and shift when bolts are removed. Maintain jack support under suspension.
   Torque spec

   Control Arm Bolts165 Nm (122 lb-ft)
7. 7

   Remove control arm from vehicle
   With all fasteners removed, maneuver the control arm out of the vehicle. You may need to rotate, tilt, or use a pry bar to work it past the frame, steering components, or brake lines. Inspect the removal path before forcing.
8. 8

   Clean mounting surfaces
   Use a wire brush to clean the frame mounting points where the control arm bushings seat. Remove rust, dirt, and debris from bolt holes and mating surfaces. Inspect frame mounting points for cracks, excessive rust, or damage.
9. 9

   Install new control arm
   Position the new control arm into the frame mounting brackets. Insert the frame mounting bolts through the bushings and frame, but do not tighten yet. Thread bolts by hand initially to ensure proper alignment. The bushings must be free to rotate at this stage.
10. 10

    Connect ball joint to knuckle
    Raise or lower the jack under the suspension to align the ball joint stud with the hole in the knuckle. Insert the ball joint stud through the knuckle. Install the castle nut and torque to specification. Align the castle nut slots with the ball joint stud hole and install a new cotter pin. Bend cotter pin ends to secure.
11. 11

    Reconnect shock absorber
    If the strut or shock absorber was disconnected, reconnect it to the mounting point on the control arm or knuckle. Install the bolt and torque to specification.
    Torque spec

    Strut Bolts115 Nm (85 lb-ft)
12. 12

    Reconnect sway bar link
    If the sway bar link was disconnected from the lower control arm, reconnect it now. Install the nut while holding the stud with an Allen key to prevent spinning. Torque to specification.
    Torque spec

    Sway Bar Link61 Nm (45 lb-ft)
13. 13

    Install wheel and lower vehicle
    Reinstall the wheel and tire assembly. Thread lug nuts by hand, then snug them in a star pattern. Lower the vehicle slowly from the jack stands until the full weight is on the suspension but wheels are still accessible. Do not fully lower to ground yet.
14. 14

    Torque control arm bolts at ride height
    With the vehicle weight on the suspension at normal ride height, torque the control arm frame mounting bolts to specification. This is critical - the bushings must be loaded at ride height to prevent premature failure. Torque both front and rear mounting bolts.
    ⚠️Control arm bushing bolts must be torqued with vehicle weight on suspension. Failure to do this will destroy bushings within a few thousand miles.
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)
15. 15

    Final torque wheel lug nuts
    Lower vehicle completely to the ground. Perform final torque on wheel lug nuts in a star pattern to specification using a torque wrench.
    Torque spec

    Wheel Lug Nuts183 Nm (135 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification
2. Verify new cotter pin is properly installed and bent
3. Double-check that control arm bolts were torqued at ride height, not with suspension hanging
4. Remove jack stands and floor jack from under vehicle

Verification

• Test drive vehicle at low speed and verify no unusual noises or vibrations
• Perform visual inspection under vehicle for any loose components or missing hardware
• Schedule front-end alignment immediately - control arm replacement will alter alignment settings
• After 50-100 miles, re-check torque on all fasteners including wheel lug nuts

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