Pitman Arm

Replace the pitman arm on a 2007-2013 Mercedes-Benz S65 AMG, disconnecting it from the steering gear and center link using proper pullers and torque specifications.

Warnings

Tools required

Parts

• Pitman arm × 1 — Use OEM specification A2214610605 or equivalent
• Pitman arm nut × 1 — Use OEM specification
• Power steering fluid × 1 — Pentosin CHF 11S

Fluids

• Pentosin CHF 11S — 1 qt

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 lock it in place using steering wheel lock or have assistant hold steady
4. Raise front of vehicle and support securely on jack stands at factory lift points
5. Remove front wheels to gain better access to steering linkage
6. Spray pitman arm nut and mounting shaft with penetrating oil and allow to soak for 15-20 minutes
7. Place drain pan under steering gear area to catch any power steering fluid spillage

Procedure

1. 1

   Access the pitman arm
   From under the vehicle, locate the pitman arm extending from the steering gear box on the driver side frame rail. The pitman arm connects the steering gear output shaft to the center link of the steering linkage. Clean the area around the connections with a wire brush to remove debris and corrosion.
2. 2

   Mark alignment reference
   Using a paint marker or scribe, mark the relationship between the pitman arm and the steering gear output shaft. This ensures proper alignment during reinstallation and maintains steering wheel centering. Mark both the arm and the shaft with corresponding alignment marks.
3. 3

   Disconnect center link from pitman arm
   Locate the ball joint connection where the center link attaches to the pitman arm. Remove the cotter pin if equipped. Using the appropriate socket, loosen and remove the nut securing the center link ball stud to the pitman arm. Use a ball joint separator or pickle fork to separate the center link from the pitman arm taper. Work carefully to avoid damaging the ball joint boot.
   ⚠Do not reuse the ball joint nut if it shows signs of damage or thread wear.
4. 4

   Remove pitman arm retaining nut
   Using a 24mm deep socket and breaker bar, loosen the large nut securing the pitman arm to the steering gear output shaft. This nut requires significant force to loosen. Once loose, remove the nut completely but leave the washer in place if present. Count the number of threads visible above the shaft before removal for reference during installation.
   ℹ️This nut is extremely tight. Ensure the steering wheel is locked to prevent gear damage.
5. 5

   Remove pitman arm from steering gear
   Install the pitman arm puller onto the pitman arm, ensuring the puller jaws are seated properly behind the arm and the forcing screw is centered on the steering gear shaft end. Tighten the puller forcing screw gradually while supporting the pitman arm. The arm will release suddenly from the tapered shaft. Never use heat or strike the arm with a hammer as this can damage the steering gear seals and bearings.
   ⚠️The pitman arm will release suddenly under pressure. Keep hands and body clear of the arm when using the puller.
6. 6

   Inspect steering components
   With the pitman arm removed, inspect the steering gear output shaft splines for damage, wear, or corrosion. Check the shaft seal for leaks. Inspect the pitman arm mounting taper and splines in the new pitman arm for any shipping damage. Examine the center link ball joint for excessive play or torn boots. Clean the steering gear output shaft thoroughly with a wire brush and wipe clean.
7. 7

   Install new pitman arm onto steering gear
   Apply a thin film of power steering fluid to the steering gear output shaft taper and splines. Align the new pitman arm with the alignment marks made during disassembly, ensuring the master spline on the shaft engages correctly. Slide the pitman arm onto the shaft, aligning the taper. Install the washer and new pitman arm nut, threading it on by hand initially.
   ⚠Do not use grease or anti-seize on the taper as this can affect the clamping force and torque specification.
8. 8

   Torque pitman arm nut
   Using a torque wrench and 24mm deep socket, tighten the pitman arm nut to specification in stages: first to 90 Nm, then to final specification of 185 Nm. Ensure the steering wheel remains locked during torquing to prevent gear rotation. Verify the alignment marks still correspond after torquing. Install cotter pin or locking device if equipped.
   ℹ️This is a critical fastener. Accurate torque is essential for safety and proper steering function.
9. 9

   Reconnect center link to pitman arm
   Position the center link ball stud into the pitman arm taper. Install the washer and nut, threading by hand initially. Using a torque wrench, tighten the nut to draw the ball stud taper fully into the pitman arm socket. Torque to specification. Install new cotter pin if equipped, bending the ends properly to lock the nut.
   ℹ️Ensure the ball stud taper is fully seated before final torquing.
10. 10

    Check power steering fluid level
    Remove the power steering reservoir cap and check fluid level. Top off with Pentosin CHF 11S fluid to the proper level marking. Start the engine and turn the steering wheel lock-to-lock several times slowly to purge air from the system. Recheck fluid level with engine running and add as necessary. Inspect for leaks around the steering gear output shaft seal.
11. 11

    Reinstall wheels and lower vehicle
    Install the front wheels, threading lug nuts by hand initially. Lower the vehicle until the wheels just contact the ground. Torque the wheel lug nuts to specification in a star pattern. Fully lower the vehicle and remove jack stands. Remove steering wheel lock.

Reassembly

1. Ensure all fasteners are torqued to specification, particularly the pitman arm nut at 185 Nm
2. Verify alignment marks on pitman arm and steering gear shaft correspond correctly
3. Check power steering fluid level and top off as needed with Pentosin CHF 11S
4. Inspect all connections for proper seating and no gaps in tapered joints

Verification

• Start engine and verify no power steering fluid leaks from steering gear output shaft seal or connections
• Turn steering wheel lock-to-lock slowly and verify smooth operation with no binding or unusual noises
• Check that steering wheel returns to center position properly
• Test drive vehicle at low speed in a safe area and verify steering response is normal with no play or looseness
• Schedule front-end alignment immediately as steering geometry has been altered
• Recheck power steering fluid level after test drive and top off if necessary

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