drivetrain

CV Axle - Rear

for 2021 Ford F-150 3.5L V6 EcoBoost · 4WD

Difficulty

Moderate

Time

1.4 h

Tools

Steps

🤖AI-generated, not yet human-verified. This walkthrough was produced by AI and may contain errors. Treat it as a guide, cross-check every step and torque value against the manufacturer's service manual, and stop if anything looks unsafe. This is a moderate-risk job — take extra care.

This procedure covers the removal and replacement of a rear CV axle on a 2021-2024 Ford F-150 with 3.5L EcoBoost engine and rear-wheel drive.

Warnings

⚠️Ensure vehicle is securely supported on jack stands before working underneath. Never rely solely on a floor jack.

⚠The axle nut is torqued to 207 lb-ft and may require significant force to loosen. Use proper technique to avoid injury.

⚠Some differential fluid may leak when the CV axle is removed. Have a drain pan ready and check fluid level after installation.

ℹ️This procedure assumes RWD configuration. AWD/4WD F-150s have different rear axle designs.

Tools required

Floor jack and jack standsEssential

Wheel chocksEssential

Torque wrench (ft-lb range)Essential

1/2 inch drive ratchet and socket setEssential

Breaker barEssential

36mm axle nut socketEssential

Pry barEssential

Hammer and punch (for staking axle nut)Essential

Wire brush

Penetrating oil

Drain pan (if differential seal is disturbed)

Parts

Rear CV axle assembly × 1 — Use OEM specification for side being replaced
Axle nut × 1 — Use new nut each time

Fluids

Motorcraft 75W-140 Synthetic Gear Oil — 0.5 qt

Preparation

Park vehicle on level ground and apply parking brake
Place wheel chocks in front of front tires
Loosen rear wheel lug nuts while vehicle is still on ground (do not remove)
Raise rear of vehicle and support securely on jack stands rated for vehicle weight
Remove rear wheel on side being serviced
Spray penetrating oil on axle nut and CV joint bolts if corrosion is present

Procedure

1
Remove axle nut
With vehicle still supported on jack stands and parking brake applied, use a 36mm socket and breaker bar to remove the rear axle nut. Have an assistant apply the brake pedal if the axle spins. Discard the old nut as a new one must be used during installation.
2
Access CV joint bolts at differential
Locate the inboard CV joint where it connects to the differential flange. You may need to rotate the axle or differential to access all bolts. There are typically 6 bolts securing the CV joint to the differential flange.
3
Remove CV joint bolts
Using a 1/2 inch ratchet with appropriate socket, remove all 6 CV joint bolts at the differential flange. Support the axle with one hand as you remove the final bolts to prevent it from dropping. Keep bolts organized for reinstallation.
4
Separate CV joint from differential
Carefully pull the inboard CV joint away from the differential flange. Use a pry bar if necessary to separate the joint, being careful not to damage the differential seal. Have a drain pan ready as some gear oil may drip out.
5
Remove CV axle from hub
Pull the outer end of the axle shaft out of the rear wheel hub assembly. You may need to tap the end of the shaft with a rubber mallet or use a puller if the splines are tight. Once free, remove the entire CV axle assembly from the vehicle.
6
Clean mounting surfaces
Use a wire brush to clean the differential flange where the CV joint mounts, and clean the hub splines. Inspect the differential seal for damage or leakage. If the seal is damaged, it should be replaced before installing the new axle.
7
Install new CV axle into hub
Insert the outboard end of the new CV axle into the rear hub assembly. Align the splines and push the shaft in until it is fully seated. The shaft should slide in smoothly; do not force it.
8
Connect CV joint to differential
Align the inboard CV joint with the differential flange, ensuring the bolt holes line up. Push the joint onto the flange and start all 6 bolts by hand before tightening any of them.
9
Torque CV joint bolts
Using a torque wrench, tighten the CV joint bolts to specification in a crisscross pattern to ensure even seating. Make at least two passes, bringing all bolts to final torque on the second pass.
Torque spec
CV Joint Bolts71 Nm (52 lb-ft)
10
Install and torque axle nut
Install the NEW axle nut onto the axle shaft at the hub. Have an assistant apply the brake pedal to prevent rotation, then torque the nut to specification using a torque wrench. After reaching final torque, stake the nut using a hammer and punch to deform the nut collar into the axle shaft groove, preventing loosening.
⚠Always use a new axle nut. Reusing the old nut can result in improper torque retention and potential axle separation.
Torque spec
Axle Nut281 Nm (207 lb-ft)
11
Reinstall wheel
Mount the rear wheel onto the hub and hand-tighten all lug nuts in a star pattern. Lower the vehicle until the tire just contacts the ground (still supported mostly by jack stands) and torque the lug nuts to specification in a star pattern.
Torque spec
Wheel Lug Nuts156 Nm (115 lb-ft)
12
Check differential fluid level
Locate the differential fill plug and check the gear oil level. Add Motorcraft 75W-140 Synthetic Gear Oil as needed to bring the level to the bottom of the fill hole. Reinstall the fill plug when level is correct.

Reassembly

Fully lower vehicle to ground and remove jack stands
Perform final torque check on wheel lug nuts with vehicle on ground
Verify axle nut is properly staked
Clean up any spilled gear oil from differential area

Verification

Test drive vehicle at low speed and verify no clicking, grinding, or unusual noises from rear axle
Verify no vibration during acceleration or deceleration
Inspect for gear oil leaks around differential seal after test drive
Verify wheel hub nut is secure and properly staked