Center Link/Drag Link

This procedure covers removal and replacement of the center link and drag link (pitman arm to center link) on a 1972 Ford F-100 with 302 V8, including tie rod end separation and steering geometry inspection.

Warnings

Tools required

Parts

• Center link (drag link assembly) × 1 — Use OEM specification or Moog DS800
• Cotter pins (1/8" diameter) × 4 — Standard automotive grade
• Tie rod end grease (if not pre-greased) × 1 — NLGI Grade 2 chassis grease

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Turn steering wheel to center position and note orientation
4. Raise front of vehicle with floor jack at frame crossmember
5. Support vehicle securely on jack stands placed under frame rails behind front suspension
6. Remove both front wheels for access (optional but recommended)
7. Spray all tie rod end castle nuts, center link tapers, and pitman arm connection with penetrating oil and allow to soak 15-20 minutes

Procedure

1. 1

   Mark thread positions and steering orientation
   Before removing any components, use a paint marker or scribe to mark the position of each tie rod end on its threaded sleeve. Count and record the number of threads visible on each tie rod end. Mark the orientation of the center link in relation to the pitman arm. These marks will allow approximate reassembly for driving to an alignment shop.
2. 2

   Remove outer tie rod end cotter pins
   At both front spindles (left and right sides), locate the tie rod end castle nuts where they connect to the steering knuckles. Straighten and remove the cotter pins using pliers or a cotter pin puller. Discard old cotter pins.
3. 3

   Loosen outer tie rod end castle nuts
   Using the appropriate socket (typically 9/16" or 5/8"), loosen but do not fully remove the castle nuts on both outer tie rod ends. Leave the nuts threaded on several turns to protect the threads and catch the spindle when the taper releases.
4. 4

   Separate outer tie rod ends from spindles
   Using a pickle fork or tie rod separator tool, drive the tool between the spindle and tie rod end to separate the tapered connection. Strike the tool sharply with a ball peen hammer. Once the taper releases (you will hear/feel a pop), remove the castle nut completely and remove the tie rod end from the spindle. Repeat for both sides. Note: If reusing tie rod ends, use a ball joint separator tool rather than a pickle fork to avoid damaging boots.
   ⚠The tie rod end may release suddenly. Keep hands clear of pinch points.
5. 5

   Disconnect center link from pitman arm
   Locate the connection between the center link and the pitman arm (coming down from the steering box on the frame). Remove the cotter pin from the castle nut. Loosen the castle nut but leave it threaded on several turns. Use the pickle fork or separator tool to break the taper between the center link ball stud and the pitman arm. Once separated, remove the castle nut.
6. 6

   Disconnect center link from idler arm
   On the passenger side of the vehicle, locate where the center link connects to the idler arm (mounted to the frame). Remove the cotter pin and loosen the castle nut. Use the separator tool to break the taper connection. Remove the castle nut completely once the taper is broken.
7. 7

   Remove center link assembly
   With all connections separated, carefully remove the center link assembly from the vehicle. The outer tie rod ends should still be threaded into the center link adjusting sleeves. If the assembly is binding, verify all tapers are fully separated and castle nuts are removed.
8. 8

   Remove tie rod ends from old center link (if reusing)
   If you are reusing the tie rod ends, loosen the adjusting sleeve clamp bolts (one on each side of the sleeves). Count and record the exact number of turns required to remove each tie rod end from its sleeve. Thread the tie rod ends out of the adjusting sleeves. If installing a new center link with new tie rod ends, skip this step.
9. 9

   Prepare new center link
   Inspect the new center link for shipping damage. Check that all grease fittings (zerk fittings) are present and threads are clean. If the center link came with adjusting sleeves and tie rod ends already installed, verify they are for the correct application (F-100 passenger side and driver side are different lengths). Wire brush all taper seats and threads.
10. 10

    Install tie rod ends into new center link
    Thread the outer tie rod ends into the adjusting sleeves on the new center link, using your thread count or marks from disassembly. Thread each tie rod end in the same number of turns as recorded during removal. Orient the adjusting sleeve clamps so the bolts face toward the rear or front of the vehicle (not up or down). Snug the clamp bolts but do not fully tighten yet.
11. 11

    Install center link to idler arm
    Position the center link assembly under the vehicle with the passenger side ball stud aligned with the idler arm. Insert the ball stud taper into the idler arm and thread the castle nut on by hand. Tighten the castle nut to seat the taper fully, then torque to 60-80 ft-lbs (estimated specification). Continue tightening if necessary to align the next castle slot with the cotter pin hole, but do not back off to align. Install a new cotter pin and bend tabs to secure.
12. 12

    Install center link to pitman arm
    Align the driver side ball stud of the center link with the pitman arm taper. Insert the ball stud and thread the castle nut on by hand. Tighten the castle nut to seat the taper, then torque to 60-80 ft-lbs (estimated specification). Align castle slots and install new cotter pin. Bend cotter pin tabs.
13. 13

    Connect outer tie rod ends to spindles
    Position each outer tie rod end ball stud into its respective steering knuckle taper hole. Thread castle nuts on by hand. Tighten castle nuts to seat tapers, then torque to 40-50 ft-lbs (estimated specification). Align castle slots with cotter pin holes (tighten further if needed, do not loosen). Install new cotter pins on both sides and bend tabs to secure.
14. 14

    Tighten adjusting sleeve clamps
    Verify that the adjusting sleeve clamp bolts are oriented correctly (clamp openings should not face directly up or down). Tighten the clamp bolts to 30-35 ft-lbs. Ensure clamps are tight enough to prevent tie rod ends from rotating in the sleeves.
15. 15

    Lubricate steering components
    If the new center link and tie rod ends have grease fittings (zerk fittings), use a grease gun to pump NLGI Grade 2 chassis grease into each fitting until you see fresh grease purge from the boot seals. Wipe away excess grease. There are typically 4 grease points: center link at pitman arm, center link at idler arm, and both outer tie rod ends.

Reassembly

1. Reinstall front wheels if removed and torque lug nuts to 100 ft-lbs in a star pattern
2. Lower vehicle from jack stands carefully
3. Remove wheel chocks

Verification

• With vehicle on ground, have an assistant turn the steering wheel slowly from lock to lock while you inspect all connections for looseness, binding, or interference
• Verify all castle nuts have properly installed and secured cotter pins with bent tabs
• Check that adjusting sleeve clamps are tight and properly oriented
• Verify steering wheel returns to approximate center position when released
• Test drive vehicle at low speed in a safe area to verify steering response before driving to alignment shop
• Schedule and complete a professional front-end alignment as soon as possible - vehicle is not safe for highway driving until aligned

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