Driving in the snow is about as polarizing as pineapple on pizza. Yet, for many, including myself, driving on a snow-covered road is something we must do to get where we need to go rather than a choice we get to make. That's why opting for an xDrive equipped BMW is one of the smartest choices we can make. An F30 3-Series with xDrive and a good set of snow tires is a nearly unstoppable force in the snow that'll make SUV owners jealous. However, the AWD capabilities add complexity to the front suspension, including, not limited to, an extra pair of axles.Replacing the front axles yourself is doable in your driveway. Think of this as an extended brake job with a few extra steps. Special BMW tools aren't required either, so sockets and wrenches are the bulk of the tools necessary. Don't get intimidated by the price of parts; with Gareth's guidance in the video below, you'll have those axles replaced in no time at all.
BMW models and years applicable:
This DIY applies to numerous BMWs extending further than just the F30. These axles fit 2-series xDrive models, 3-series xDrive, and 4-series xDrive, although the process will be slightly different depending on the model.
Symptoms of a failing front axle on a BMW F30:
- Knocking sound under acceleration
- Clicking sound while turning
- Grease covering the inside of the wheel or tire
The axle in your BMW is comprised of two CV joints on either end of a shaft. The CV joint allows the engine's forward rotational force to drive the wheels at different angles without increasing resistance. They are packed with grease and use a rubber boot to seal the internal components and grease from dirt.
A lot of the sounds from failing front suspension and drivetrain components make similar noises. The critical difference is when they happen. Axle and CV joint issues are most apparent while first accelerating and while turning. A CV joint's worn components lead to excessive play within the joint, creating a distinct knocking or clicking sound.
The worn components of a failed axle usually happen for one of two reasons. Either they've been used for so long that friction eventually wears them down enough to cause significant play, or the boot rips and allows the grease to escape. The escaping grease gives less wear protection to the CV's components and attracts dirt, which can further wear and destroy the CV joint's components. Regardless of how they fail, you should replace them as soon as you can.
How much will it cost to replace the front axles on a BMW F30?
You may want to sit down while reading this bit. Genuine replacement axles are not cheap; two new front axles will cost around $1900 alone. Then tack on another $45 for the axle seals and axle bolts. Budget an even $2000 for the job's cost to allow room for extra rags, brake clean, or tools.
Regardless of the astronomical price, doing it yourself will be cheaper than taking it to a dealership. On top of their price cost, which is marked up, you'll be paying nearly $200/hr on labor. The total cost for parts and labor will hover around the $2500 mark.
How long will it take to replace the front axles on a BMW F30?
Time spent on the job will be determined by where you live and what you need to do. Set aside a few hours if you need to replace both axles and a little over an hour for one of them. Any corrosion present will add extra time to the job. Rust penetrant and A MAP gas torch will help to free anything stuck.
Parts required to replace the front axles on a BMW F30:
Tools required to replace the front axles on a BMW F30:
- 8mm Socket
- 13mm Socket
- 17mm Socket
- 21mm Socket
- T40 Torx Bit Socket
- 6mm Hex Bit Socket
- 17mm Hex Bit Socket
- 21mm Wrench
- Pry Bar
- Torque Wrench
- Brass Drift
Steps required to replace the front axles on a BMW F30:
Step 1: Remove the axle nut
Jack up the front of the car and place it onto jack stands. Then use a 17mm socket to remove the lug bolts.
If your F30 has xDrive, you need to remove the axle from the hub to have enough space to remove one of the arms. Use a 17mm hex bit socket to remove the axle bolt from the hub. If you don't have xDrive, skip to the next step and ignore any axle-related talk.
With the bolt out, you can pull the axle away from the hub when you need to.
Step 2: Remove the brake caliper and rotor
One of the front calipers has a pad wear sensor on it. You can remove the sensor from the pad or disconnect it at the connection on the strut. Then, use an 18mm socket to remove the two caliper bracket bolts from the knuckle. That will separate the caliper from the knuckle, so you'll need some zip-ties or bungee cord to hang the caliper out of the way.
A set screw secures the rotor to the hub. Use a 6mm hex bit socket to remove the screw. If the rotor doesn't want to come free of the hub, give the hat a few raps with a hammer. That should be enough to break the corrosion and free the rotor.
Step 3: Free the knuckle and remove the axle
The knuckle needs room to be moved out of the way to get the axle out of the car. To achieve this freedom, use a 21mm wrench to remove the nut for the lower control arm and a T40 Torx bit socket to counter hold the ball joint.
Now there's enough space to pull the axle out. The best way to pop the axle out is to get underneath the car and use a hammer and punch. There's an access hole in the reinforcement plate under the vehicle that gives you just enough space to see the end of the axle. Place the brass punch against it and hammer away until the axle has slid out most of the way.
Step 4: Replace the axle seal
While you have the axle out, you may as well replace the axle seal; there won't be an easier time to do it. You can use a pry bar to remove the old seal without removing anything else, but it won't be easy. The easiest way to get better leverage on it is to remove the reinforcement plate under the car.
Use a 13mm socket to remove the many bolts holding on the reinforcement plate. You'll have direct access from beneath the seal to pry it out. Use a pry bar, screwdriver, or something similar to pop out the old seal. Have a rag handy to wipe up any oil that may come out of the differential.
Wipe the sealing surface to ensure no debris is present, and then fit the new seal. You'll be able to press in the seal by hand partially. Then get the largest socket you have, close to 30mm if you can. Press the socket against the seal and use it as a tool to help drive in the seal.
Hammer on the socket and drive in the seal until it bottoms out. Then, lubricate the inside of the seal with oil to aid in the new axle's installation.
Step 5: Install the new axle
Take the new axle and slid it into the differential. The snap-ring on the axle's end needs to fit into the differential, so you need to drive the axle in with a hammer until it bottoms out.
After that, put the axle's outer end into the back of the knuckle, then refit the lower control arm. The axle must be in place before getting the ball joint in the knuckle.
Once they're both in place, thread on the nut for the lower control arm by hand. Then, use a 21mm wrench to tighten the nut and a T40 Torx bit socket to counter-hold the threads. Then, use a 21mm socket to torque the ball joint nut to 175Nm.
Next, thread in the axle bolt by hand. Ensure the threads of the bolt and the splines on the hub and axle engage before tightening. Use a 17mm hex bit socket to drive in the axle bolt.
Once both axles are fitted, refit the reinforcement plate to the underside. Use a 13mm socket to drive in its mounting bolts.
Step 6: Refit the brakes and wheels
Use a brush, brake clean, and rages to clean off any corrosion if present. Then, refit the rotor to the hub and secure it with its set screw. Use a 6mm hex bit socket or Allen-wrench to tighten the screw. Then, slide the caliper back into place and thread in its two mounting bolts. Thread in the bolts by hand before torquing them to 110Nm with an 18mm socket. Reconnect the pad wear sensor too!
Then, use a 17mm hex bit socket to torque the axle bolt to 210Nm, plus 90° of rotation. If you can, have a helper hold the brake pedal down to stop the hub from rotating and allow you to torque the axle nut. Otherwise, place a heavy-duty screwdriver through the caliper bracket and into the rotor's vanes to hold the wheel hub.
Lastly, refit the wheels and thread in the lug bolts before tightening them with a 17mm socket.
BMW F30 Front Axle Torque Specs:
- BMW Thrust Arm Ball Joint Nut = 175Nm or 129 ft-lbs, of torque
- BMW Axle Bolt = 210Nm or 155 ft-lbs, of torque, plus 90°
For the monumental cost of parts of the job, the replacement process is very straightforward. If you've made it to the end, you should be click and knock free on your future drives. If you're interested in more DIYs for your BMW, you can visit bmw.fcpeuro.com and subscribe to our YouTube channel.