Parts used are for a 1995 M3. Check www.realoem.com to find the correct part numbers for your model of E36.
Parts:
1. Front wheel hub assembly, part #31226757024
- Tech Tip: there are several manufacturers of these hubs, and not all are up to the same standards. Use only the wheel hubs manufactured by the companies FAG or Lemfoerder, as these are the OEM suppliers.
3. Dust cap, part #31211130124 (can be reused)
4. Rear dust collar, part #31211136466 (can be reused)
Disposable Items:
1. WD-40, PB Blaster, etc.
2. Brake Cleaner (lots of this)
3. CRC Brake and Caliper grease
4. Assembly grease
5. Rubbing alcohol
6. Gloves
7. Wire brush
8. Zip ties
Tools:
1. Metric sockets
2. Metric Hex sockets
3. Metric Allen keys
4. Flat head screwdrivers
5. Mallet
6. Breaker bar and/or metal pipe
7. Brake pad spreader/C-clamp
8. Various pliers
Specialty Tools:
1. Torque wrench capable of reaching 250ft-lb, preferably 3/4" drive
2. 46mm or 1 13/16" socket
3. 3-jaw bearing puller (used for removing hub, may not be necessary)
4. Dremel or other small rotary tool
As always, you will want your car firmly supported by jack stands at the factory jack points. Even though you can see my car was at an incline while working on this and several other projects, i must insist that you always work on your car on flat, level ground. Failure to do so can result in severe injury.
With the wheel off, pause a moment to look at the scene in front of you. As always, i like to inspect everything in the area that im working on to look for other issues to address. Take this time to inspect items such as your tie rods and control arm joints, your wheel well liners, sway bar bushings and links, etc, etc. You will appreciate the workings of your car much more when doing this, and gain a much broader understanding of how things work.
Wheel off
1. First you will be removing the brakes, so if you have done a brake job before this part will be second nature. Use a screwdriver to remove the anti-rattle clip and a pair of needle nose pliers to remove the wear sensor from the pad.
Anti-rattle clip removed and wear sensor un-plugged.
2. Behind the caliper you will see the caliper guide boots. Remove the two rubber caps to reveal the heads of the guide bolt. Using a 7mm hex socket unbolt the guide bolts from the caliper. Once they are free from the mounting bracket, pull them away from the brake disc as to allow the caliper to be removed. The bolts should NOT come out completely from the guide boots.
- Tech Tip: Make sure any hex sockets you use are square in their holes' before applying any pressure to the ratchet. These bits are very susceptible to braking when torqued in a way other than intended. Here's the first broken tool of the day, good thing theres a Sears close by.
Weaksauce
3. At this point, you can begin to remove the caliper. Chances are the piston will still be firmly holding to the brake disc. Using a screwdriver, gently wedge it and pry away the caliper from the mounting bracket. If you are re-using the brake pads, be careful not to score them while doing this.
Wedge screwdriver against the disk to pry away the caliper.
With the caliper separated from the carrier, you will need to unhook the brake line from the strut and support the caliper as to not put stress on the hose. Using a few heavy duty zip-ties, attach the caliper to a the coil of your front spring. This will place the caliper up and out of your way while you work. NEVER ever let your caliper hang from the hose. Aside from zip-ties, many people have used wire hangers to hold up the caliper with success.
- Tech Tip: Now as ive said before, you should be in the habit of checking all the components in the area youre woking on. This is a perfect opportunity to inspect you brake calipers. Check the piston boot and guide boots for tears, make sure the is no serious rust, and that all lines are free of cracks. Rarely do we have the time to inspect brakes unless we are changing them, so use this time wisely.
4. Next remove the caliper mounting bracket using a 16mm socket. These bolts are torqued to 81ft-lbs, so expect to have to pull a bit. Slide the caliper bracket off away from the brake disk.
5. Then with a 6mm allen key, you can remove the brake disk set screw and remove the brake disk, exposing the wheel hub. Set both the brake disk and caliper bracket aside until you are ready to reassemble them.
Brakes removed, caliper zip-tied to coil spring
6. Finally, we can see the hub by itself. With a flat-head screwdriver, slowly pry away the outer dust cap being careful not to bend it.
7. Behind the dust cap you will find the 46mm retaining nut. As you can see, this aluminum nut will be scored from the factory and bent into the notches on the spindle. Like a cotter pin, this is a last ditch effort to let you know the hub may be coming off.
With a screwdriver, tap out the bent in tab. It will most likely break off.
Hub retaining nut
8. Now its time to break the retaining nut. You will be needing your 46mm or 1 13/16" socket, a breaker bar, and possibly a metal pipe for extra leverage. Attach everything with the breaker bar extending to the front of the car. Then with the socket squarely on the nut, press down giving good even pressure on the bar until the nut breaks free. Its torqued to over 200ft-lb, so you will find this difficult without the proper leverage.
- Tech Tip: Twist the hub (or steering wheel) so that the front of the spindle is pointing out from the car. This will help to avoid you scratching your bumper/fender.
- Tech Tip: Now you may be asking why am i using an SAE socket on a metric job? Convenience really, this 1 13/16" socket by itself was about $20 from Sears where they sell 3/4" drive sockets separately. In fact, the size difference between the two are negligible. Converted to decimal inches, 1 13/16" is equivalent to 1.812" where 46mm is equivalent to 1.811".
If you are looking for an exact metric set, i would recommend the 3/4" drive socket set from Harbor Freight. It's a 10pc set which includes a 46mm socket along with several other sizes for about $60.
9. This is where most people's experiences with replacing a hub diverts into easy and ridiculous. Once the retaining nut is off, you will need to remove the old hub off the spindle. Now on mine, all i had to do was tap it from behind with a mallet and the entire assembly came off in one peice.
Hopefully this is how yours will come off as well, though lets go through the process of the worst case scenario of where the hub assembly is fused to the spindle (sorry, no pictures for this part).
- 1. If the hub will not budge on the spindle, you will need the leverage of a slide hammer to remove it. Get your brake disk and lug bolts that you previously removed.
2. Place the disk in position on the hub with the holes aligned, and then thread the lug bolts only a few turns into the hub leaving plenty of room for the disk to move back and forth.
3. With firm quick motions, jerk the brake disk back as you would a slide hammer to pull the hub off the spindle. Take care to steady yourself when doing this, you may easily fall back when the hub releases from the spindle.
Additionally, if you had to remove the hub this way, you will most likely have part of the inner race (the inner metal cylinder on the hub that mates to the spindle shaft) still stuck to the spindle. At this point you have two options to remove it.
4a. If you were able to procure a 3-jaw puller, you will want to secure the three jaws around the inner race. Then extend the threaded shaft into the center of the spindle until you are able to pull it off. If there is not enough threads on the puller to reach the base on the inside of the spindle, you will need to stack washers on the inside of the spindle shaft until you are able to gain enough height to use the puller effectively.
4b. The material for that inner race is soft enough to cut away with a Dremel. Carefully make a cut down one side and see if it can be tapped out. If not, then make an additional cut down the opposite side to remove it completely. BE CAREFUL! You do not want to cut into the spindle shaft by accident.
10. With the old hub removed, take an inventory of what you see in front of you. You should have the inner dust cap, ABS sensor, and dust shield. During this project i noticed a crack down the down the side on the large dust shield, so i took the opportunity to remove it and have the crack welded.
As well, i used some rubbing alcohol and a clean rag to clean the grime off the ABS sensor. Additionally, you may want to pull out the inner dust seal and inspect it for damage. Mine was in good condition, so i just cleaned it off and replaced it.
- Tech Tip: You cannot remove the front dust shield on an E36 without removing the hub assembly again. Use this opportunity to make any repairs or bends that you need to the shield.
11. With the dust shield and inner dust cap back in place, you can proceed with installing the new hub assembly. First spray down the spindle with brake cleaner and use a wire brush to remove any grime, especially at the threads. Then coat the spindle with a small about of grease to aid in pressing on the new hub.
Get out your new hub assembly and inspect it over, then proceed to position it on the spindle. You will not be able to press it in by hand, so get out the 1 13/16" socket and position it over the inner race of the new hub as seen below. Then use your mallet to hit the socket, tapping the hub assembly farther and farther onto the spindle. At some point during your hammering, you will feel the hub reach the very back of the spindle and stop advancing. Done correctly, you should now be able to spin the hub without the inner race moving.
Using the socket to hammer the new hub onto the spindle.
12. With the hub in place, get your new 46mm retaining nut and spin it on to the spindle. You will only be able to get it so far until it stops at the bearing. Now its time to pull out your 3/4" torque wrench (or other torque wrench capable of 250ft-lb) to tighten the retaining nut. Set the torque wrench between 215 and 225ft-lb, and with your 1 13/16" socket, proceed to torque the nut. With the leverage from such a long wrench, you will reach the desired torque faster than you may think, so be careful.
- * Retaining nut (46mm): 215ft-lb
Big ass torque wrench
- Tech Tip: The retaining nut is made of a soft material and is not designed to be reused. Only install a new hub with a new nut. Reusing the original retaining nut can lead to the failure of the part and severe injury.
Torquing the retaining nut.
13. You will notice that the new retaining nut does not come pre-cut for the tabs that bend into the notches on the spindle, you will have to make these yourself. Using your Dremel tool and a steady hand, make four cuts, two on each side, no more than about 5mm deep. These will form the tabs that will be later bent into the spindle.
- Tech Tip: Sparks will fly during this process of cutting the retaining nut. Wear proper eye protection.
Retaining nut tab's formed with cutting tool
14. With this done, you can proceed with tapping the newly formed tabs into the spindle notches. Continue to tap them in until they are at a 90 deg. angle in relation to their original position. Then finish up by tapping the outer dust cap back onto the center of your new hub assembly, sealing in the retaining nut from the elements.
Tabs bent in to spindle
15. This concludes the replacement of the wheel hub assembly. From here you can simply follow the reverse procedure for brake removal to complete the project. Lets quickly cover these steps.
a. Replace the rotor onto the hub and tighten the brake set screw using a 6mm allen wrench.
- Tech Tip: Spray a coat of WD-40 on the inside and outside mounting area of the brake disk to help prevent rusting between the two surfaces.
b. Reinstall the brake carrier bracket using a 16mm socket and torque accordingly.
c. The piston may have extended out from the caliper while it was off, not allowing enough room to slide caliper onto the brake disk. Use a brake pad spreader or C-clamp to push it back into its housing.
d. Then take some CRC caliper grease and lube up the caliper guide bolts, guide boots, brake pad guides and any area they would slide against.
e. Slide on the caliper in position on the carrier bracket, then tighten the caliper guide bolts using a 7mm hex socket and torque accordingly
f. Reposition any brake lines and wires on their appropriate mountings. Use a pair of pliers to press the Brake Pad Wear Sensor back into the brake pad.
g. Replace wheel and torque the lug nuts/bolts accordingly.
- * Brake Carrier Bracket (16mm): 81ft-lb
* Caliper Guide Bolts (7mm hex): 22ft-lb
* Wheel to Hub Assembly (17mm): 75-80ft-lb
Congratulations! You have now completed the install for a new wheel hub onto your E36. Now take the time to go for a drive and feel smug in knowing that you just did something that 99% of BMW owners would have had taken their car to the dealership for.
