CV Boot - Inner

Replace the inner CV boot on the rear axle halfshaft to prevent grease loss and CV joint contamination on the 2007-2013 Mercedes-Benz S65 AMG.

Warnings

Tools required

Parts

• Inner CV boot kit with clamps × 1 — Use OEM specification
• CV joint grease × 1 — Typically included in boot kit
• Differential cover gasket × 1 — Use OEM specification
• Axle nut (if staked type) × 1 — Use OEM specification

Fluids

• Mercedes-Benz Diff Fluid 75W-85 — 2 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen rear wheel lug nuts while vehicle is on ground
3. Raise rear of vehicle and support securely on jack stands at manufacturer-approved jacking points
4. Remove rear wheel on affected side
5. Place drain pan under differential area to catch fluid spillage
6. Mark orientation of halfshaft to differential flange for reassembly alignment

Procedure

1. 1

   Remove halfshaft from differential
   Remove the six CV bolts connecting the inner CV joint to the differential flange using a socket and breaker bar. Support the halfshaft to prevent it from dropping. Once bolts are removed, carefully pull the halfshaft away from the differential. Differential fluid will drain from this opening, so ensure drain pan is positioned correctly.
   Torque spec

   CV Bolts82 Nm (61 lb-ft)
2. 2

   Remove halfshaft from hub
   Remove the axle nut from the outer end of the halfshaft (nut is visible through wheel hub). If nut is staked, it must be replaced. Use a breaker bar and appropriate socket. With nut removed, push the halfshaft inward through the hub assembly to free the outer splines. You may need to tap the end with a plastic mallet. Completely remove the halfshaft from the vehicle.
   Torque spec

   Axle Nut250 Nm (184 lb-ft)
3. 3

   Remove old inner CV boot
   Secure the halfshaft in a vise using soft jaws to protect the shaft. Cut or grind off the old boot clamps on the inner CV joint side. Slide the old boot toward the outer joint to expose the inner CV joint. Wipe away old grease and inspect the joint for wear, pitting, or damage. If the joint is damaged, the entire halfshaft assembly should be replaced.
4. 4

   Clean and inspect CV joint
   Thoroughly clean the inner CV joint housing and tripod bearing with cleaning solvent. Inspect all bearing surfaces, races, and the tripod for wear or damage. Check the shaft for damage where the boot seats. Clean the shaft surface where the new boot will be installed. If separating the CV joint, mark the tripod orientation to the shaft before removal.
5. 5

   Install new inner CV boot
   Slide the new boot clamps onto the shaft first, followed by the new boot. Position the small end of the boot on the shaft in the correct groove. Install the small clamp but do not fully tighten yet. Pack the CV joint with the specified amount of grease from the boot kit (typically the entire contents). Slide the boot over the CV joint housing and ensure it seats properly in the groove on the housing.
6. 6

   Secure boot clamps
   Ensure the boot is not twisted and is properly seated in both grooves. Equalize air pressure in the boot by inserting a small blunt tool between boot and housing, then remove tool. Using boot clamp pliers or crimping tool, secure the small clamp first, then the large clamp. Ensure clamps are tight and properly crimped to prevent grease leakage.
7. 7

   Reinstall halfshaft to hub
   Clean the hub splines and apply a thin coat of anti-seize to the outer CV joint splines. Insert the halfshaft through the hub assembly, ensuring splines engage properly. Install a new axle nut (if staked type) and hand-tighten. Do not torque the axle nut until the wheel is reinstalled and vehicle is on the ground.
8. 8

   Reconnect halfshaft to differential
   Clean the differential flange and halfshaft flange mating surfaces. Align the halfshaft to the differential flange using the alignment marks made during disassembly. Install the six CV bolts and hand-tighten. Torque the CV bolts to specification in a star pattern to ensure even seating.
   Torque spec

   CV Bolts82 Nm (61 lb-ft)
9. 9

   Refill differential fluid
   Check the differential fluid level through the fill hole on the differential housing. Add Mercedes-Benz Diff Fluid 75W-85 as needed until fluid begins to weep from the fill hole. The differential should hold approximately 2 quarts total. Install and torque the fill plug to specification. If significant fluid was lost, consider changing the differential fluid completely.
10. 10

    Reinstall wheel and torque axle nut
    Install the rear wheel and hand-tighten lug nuts. Lower the vehicle until the tire just contacts the ground (weight on tire but vehicle still supported by jack). Torque the axle nut to 250 Nm. If using staked-type nut, stake the nut into the shaft groove using a punch. Fully lower the vehicle and torque wheel lug nuts to specification in a star pattern.
    Torque spec

    Axle Nut250 Nm (184 lb-ft)

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification in the proper sequence
2. Verify no tools or parts are left in the work area
3. Check for any fluid leaks around the differential and CV boot clamps
4. Test drive the vehicle and listen for any clicking or unusual noises from the CV joints

Verification

• Inspect the new CV boot for proper seating and no tears or damage
• Verify boot clamps are tight and secure with no movement
• Check differential fluid level is correct with no visible leaks
• Test drive vehicle through full steering range and acceleration to verify no CV joint noise
• Recheck axle nut torque after 50-100 miles of driving
• Inspect boot and clamps again after first drive cycle for any grease seepage

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