CV Boot - Outer

This procedure replaces the outer CV boot on a 2019 Mercedes-Benz G-Class with 4.0L Turbo V8 engine, requiring wheel removal, axle disconnection, and boot replacement with new clamps and grease.

Warnings

Tools required

Parts

• Outer CV boot kit (includes boot, clamps, and grease) × 1 — Use OEM specification
• Axle nut (single-use) × 1 — Use OEM specification
• CV joint retaining circlip (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake.
2. Chock rear wheels securely.
3. Verify which side (left or right front) requires the CV boot replacement.
4. With vehicle still on ground and transmission in Park, use breaker bar to loosen (but do not remove) the front axle nut approximately 1/4 turn.
5. Loosen wheel lug nuts approximately 1/4 turn while vehicle is on ground.
6. Raise front of vehicle with floor jack at designated lift points and support on jack stands at manufacturer-specified support points.
7. Remove wheel lug nuts completely and remove wheel.
8. Clean work area around CV joint, hub, and suspension components with degreaser and wire brush to prevent contamination.

Procedure

1. 1

   Remove axle nut
   With vehicle supported on jack stands, completely remove the front axle nut using a socket and breaker bar. The nut should already be loosened from preparation steps. Remove and discard the axle nut as it is single-use only. Set aside for replacement with new hardware.
2. 2

   Disconnect lower control arm or tie rod
   To provide clearance for axle removal from hub, disconnect the lower ball joint from the steering knuckle. Verify the exact retention method against the FSM for the W463 front suspension (the lower ball joint stud is typically secured by a nut, not a Torx pinch bolt). Remove the ball joint retaining nut, then use a ball joint separator to separate the ball joint taper from the knuckle. If resistance is encountered, use a proper ball joint separator tool to break the taper. Avoid hammering directly on the knuckle casting, as the aluminum front knuckle on this platform can crack. Support the control arm to prevent strain on suspension components.
3. 3

   Press axle shaft from hub
   With the lower suspension disconnected, push the axle shaft out of the wheel hub assembly. The shaft should slide out with moderate hand pressure. If the shaft is stuck, use a brass punch through the center of the hub and tap gently on the axle shaft threads while pulling the knuckle outward. Do not damage the axle threads. Once the splined shaft is clear of the hub, pivot the knuckle assembly outward to gain working clearance. Support the axle shaft to prevent it from hanging by the inner CV joint.
4. 4

   Remove outer CV boot clamps
   Locate the two clamps (large and small) securing the outer CV boot to the joint housing and axle shaft. Use CV boot clamp pliers or side cutters to cut and remove both clamps. Discard the old clamps. Slide the boot away from the outer CV joint toward the center of the axle shaft, exposing the CV joint housing and grease.
5. 5

   Mark and separate outer CV joint
   Before disassembly, use a marker or scribe to mark the relationship between the outer CV joint housing and the axle shaft for proper reassembly alignment. Locate the circlip or retaining ring inside the CV joint that secures it to the axle shaft. Depending on design, you may need to expand the circlip with snap ring pliers while pulling the CV joint housing off the shaft, or the joint may simply pull off after sufficient force. Pull the outer CV joint straight off the axle shaft with a twisting motion if necessary. The joint should separate with moderate force. If a circlip is present, inspect it for wear or damage and replace if necessary.
6. 6

   Clean axle shaft and inspect components
   With the outer CV joint removed, slide the old boot completely off the axle shaft. Thoroughly clean the axle shaft splines and CV joint mounting surface with degreaser and shop towels, removing all old grease. Inspect the axle shaft for wear, scoring, or damage. Inspect the CV joint itself for excessive play, worn races, or damaged balls. Check the joint for smooth rotation in all directions—any binding, clicking, or roughness indicates internal wear. If the CV joint shows wear beyond the boot, the entire joint or axle assembly may require replacement.
7. 7

   Install new outer CV boot onto axle shaft
   Slide the new outer CV boot (small end first) onto the axle shaft from the outer end. Position the small end of the boot in the groove on the axle shaft. Do not install clamps yet. Ensure the boot is not twisted and sits properly in its designated groove.
8. 8

   Pack CV joint and reinstall
   Pack the outer CV joint housing with the grease provided in the CV boot kit, distributing it evenly throughout the joint interior and between the ball bearings. Use approximately half of the grease packet inside the joint housing. Apply the remaining grease to the axle shaft splines. Align the reference marks made during disassembly and slide the outer CV joint back onto the axle shaft, ensuring the circlip (if equipped) seats properly in its groove. You should hear or feel a click when the circlip engages. Verify the joint is fully seated by attempting to pull it off the shaft—it should not move.
9. 9

   Position boot and install clamps
   Pull the large end of the CV boot over the outer CV joint housing and seat it in the groove on the joint housing. Ensure the boot is not twisted or stretched. Release any trapped air by carefully lifting the boot edge with a small screwdriver to equalize pressure, then reseat. Install the small clamp on the axle shaft end of the boot first, positioning it in the boot groove. Tighten the clamp securely using CV boot clamp pliers or the appropriate tool until the boot is sealed against the shaft. Install the large clamp on the joint housing end of the boot in the same manner, ensuring a secure seal. Verify both clamps are tight and the boot has no twists or kinks.
10. 10

    Reinstall axle shaft into hub
    Carefully guide the outer end of the axle shaft back through the wheel hub bearing, aligning the splines. Push the shaft through until the threaded end protrudes through the hub face. You may need to rotate the shaft slightly to align the splines. Ensure the shaft is fully seated into the hub bearing. Pivot the steering knuckle back into alignment with the lower control arm ball joint.
11. 11

    Reconnect lower suspension
    Reconnect the lower control arm ball joint to the steering knuckle, aligning the ball joint taper with the knuckle bore. Install the ball joint retaining fastener (verify whether it is a nut or pinch bolt per FSM) and tighten to the manufacturer-specified torque. Ensure the ball joint is fully seated in the taper before torquing. Verify suspension components move freely without binding.
12. 12

    Install new axle nut
    Thread the new axle nut onto the axle shaft by hand as far as possible. Use a socket to snug the nut, but do not torque to final specification yet. The nut will be torqued to final specification after the wheel is reinstalled and the vehicle is lowered to the ground.
13. 13

    Reinstall wheel and lower vehicle
    Reinstall the wheel onto the hub, aligning the lug bolt holes. Thread all lug nuts by hand to prevent cross-threading. Snug the lug nuts in a star pattern with a wrench, but do not torque to final specification yet. Carefully lower the vehicle from jack stands using the floor jack until the tire contacts the ground with partial weight on it. Remove jack stands and lower vehicle completely to the ground.
14. 14

    Torque axle nut and wheel lug nuts to specification
    With the vehicle on the ground, parking brake engaged, and transmission in Park, torque the axle nut to the manufacturer-specified value for the W463 front axle (verify exact Nm and any torque-angle sequence in the FSM before proceeding) using a calibrated torque wrench. If the axle spins, have an assistant apply the brake pedal while torquing. After the axle nut is torqued, torque all wheel bolts to the manufacturer-specified value (approximately 150 Nm; verify exact spec for the fitted wheels in the FSM) in a star pattern to ensure even seating. Perform a final verification that all fasteners are tight.

Reassembly

1. Reassembly is included in the procedure steps above.
2. Ensure the new CV boot is not twisted and both clamps are securely tightened.
3. Verify the CV joint circlip is fully engaged on the axle shaft.
4. Confirm the axle shaft is fully seated in the wheel hub bearing before torquing the axle nut.

Verification

• Start the engine and turn the steering wheel lock-to-lock while stationary to verify no binding or unusual noises from the CV joint.
• Test drive the vehicle at low speed in a safe area, performing tight turns in both directions. Listen for clicking or popping noises that would indicate CV joint issues.
• After test drive, inspect the new CV boot for any signs of grease leakage, tears, or improper seating.
• Verify there is no excessive play in the axle shaft by attempting to move it radially with the wheel reinstalled—movement should be minimal.
• Recheck axle nut and wheel lug nut torque after 50-100 miles of driving to ensure proper retention.

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