Center Link/Drag Link

This procedure covers the replacement of the center link and drag link on a 2007 Ram 3500 with 5.9L Cummins diesel and 4WD, which are critical steering components connecting the steering box to the front wheels.

Warnings

Tools required

Parts

• Center link (relay rod) × 1 — Use OEM specification or heavy-duty aftermarket
• Drag link (steering connecting rod) × 1 — Use OEM specification or heavy-duty aftermarket
• Castle nuts for tie rod ends × 4 — Typically included with new links
• Cotter pins × 4 — 1/8 inch diameter

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Turn steering wheel to center position and note position
4. Raise front of vehicle with floor jack and support securely on jack stands under frame rails
5. Remove both front wheels
6. Spray all tie rod end tapers and castle nuts with penetrating oil and allow to soak for 15-20 minutes

Procedure

1. 1

   Remove castle nuts from drag link ends
   Remove the cotter pins from both ends of the drag link (one at the pitman arm and one at the passenger-side knuckle). Using appropriate socket, remove the castle nuts from both drag link tie rod ends. Do not discard nuts if reusing old drag link for reference.
2. 2

   Separate drag link from pitman arm and knuckle
   Using a tie rod end puller or pickle fork, separate the drag link ball stud from the pitman arm. Then separate the opposite end from the passenger-side steering knuckle. The drag link can now be removed from the vehicle. Note the orientation and any adjustment positions if applicable.
3. 3

   Remove castle nuts from center link ends
   Remove cotter pins from both tie rod end connections at the driver and passenger steering knuckles. Remove both castle nuts using appropriate socket and wrench.
4. 4

   Separate outer tie rod ends from knuckles
   Using tie rod end puller, separate both outer tie rod ends from the driver and passenger side steering knuckles. Support the center link assembly as you work to prevent it from falling when the last connection is separated.
5. 5

   Separate center link from idler arm
   Using a tie rod end puller, separate the tie rod ends from both steering knuckles and remove the tie rod assembly from the vehicle. If tie rod ends are being reused, mark their thread position for reassembly.
6. 6

   Transfer outer tie rod ends if reusing
   If reusing the outer tie rod ends, count and record the number of threads showing on each side before removal. Remove outer tie rod ends from old center link and install onto new center link at the same position. This maintains approximate alignment. Apply anti-seize to threads during installation.
7. 7

   Clean all taper seats
   Use wire brush to clean the taper seats on both steering knuckles, the pitman arm, and the idler arm. Remove all rust, dirt, and old grease. Clean taper surfaces ensure proper seating and prevent premature wear.
8. 8

   Install new center link to idler arm
   Position the new tie rod and insert the ball studs into both steering knuckles. Install new castle nuts and tighten firmly. Ensure the tapers are fully seated. Do not install cotter pins yet - final tightening will occur after all connections are made.
9. 9

   Connect outer tie rod ends to knuckles
   Insert the outer tie rod end ball studs into the steering knuckles on both driver and passenger sides. Install new castle nuts and tighten until ball stud tapers are fully seated and the castle nut aligns with the cotter pin hole. Install new cotter pins and bend tabs to secure.
10. 10

    Install new drag link
    Position the new drag link with one end at the pitman arm and the other at the passenger-side knuckle connection point on the center link or knuckle (depending on configuration). Insert ball studs into their tapered seats. Install castle nuts on both ends and tighten firmly to seat tapers.
11. 11

    Torque all castle nuts and install cotter pins
    Since specific torque values are not provided in the database, tighten all castle nuts to manufacturer specification (approximately 100 ft-lbs for the tie rod and drag link ball stud nuts on this heavy-duty vehicle - verify exact values with the factory service manual). Tighten to align castle nut slots with cotter pin holes - never loosen to align. Install new cotter pins at all ball stud connections (two tie rod ends at the knuckles and both drag link ends) and bend tabs securely.
12. 12

    Inspect steering system operation
    With vehicle still on jack stands, manually check all connections for proper seating and tightness. Verify all cotter pins are properly installed. Have an assistant turn the steering wheel slowly from stop to stop while you observe all linkage for binding, excessive play, or interference. All components should move smoothly without binding.

Reassembly

1. Reinstall both front wheels and torque lug nuts to specification (typically 135 ft-lbs for steel wheels, verify for your wheel type)
2. Lower vehicle to ground and remove jack stands
3. Check power steering fluid level and top off if necessary with ATF+4

Verification

• Start engine and turn steering wheel slowly from lock to lock, listening for unusual noises or binding
• Check all tie rod end connections for leaks or movement while assistant turns steering wheel
• Test drive vehicle at low speed in a safe area to verify steering response
• Schedule a professional wheel alignment as soon as possible - alignment will be significantly affected by this repair
• After 50-100 miles, re-check all castle nuts for proper torque and verify cotter pins are secure

More procedures for this vehicle