E46Fanatics - View Single Post - Ridiculous Differential Noise
View Single Post
Old 09-23-2013, 10:42 AM   #54
Registered User
Join Date: Sep 2012
Location: Old Greg's Cavern
Posts: 12,675
My Ride: '13 128i, '04 330Ci
Rear Wheel Bearing DIY

So here's a short description of what I did, and some lessons learned.

As of December 13, 2013, BMAParts.com has the best price on F.A.G. bearings ($38)

  • Harbor freight front wheel bearing kit
  • AutoZone Slide hammer
  • AutoZone axle puller (crow foot lookin thing)
  • 5/8"-18 threaded, pointy tip bolt
  • 1-1/16" and 1-1/4" wrenches for the HF bearing tool
  • E12 external torx socket for drive axles
  • large Torque wrench capable of >225 ft*lbs
  • Dremel with cutoff wheel
  • Silicone lube spray to lube the HF tool bolts while turning (help a good bit)
  • 36 mm 12 point 1/2" drive (at least) socket
  • SNAP RING PLIERS. This snap ring is large, and a nice pair of snap ring pliers is so worth it.
  • Assorted 1/2" and 3/8" extensions
Important Bolt Torques (for my 2004 330Ci)

Caliper Carrier bolts (50 ft*lbs)
Caliper pins (22 ft*lbs)
Axle to Diff bolts (75 ft*lbs)
Axle nut (221 ft*lbs)

I hand tightened everything else.

Wear safety glasses almost for the entire job. When you're turning these bolts, you'll see what I mean. The last thing you want to happen is for one of these bolts or wrenches to snap under 250 ft*lbs of torque and god knows what load. I wore them with pressing the axle, pressing the bearing in/out, hammering the hub, cutting the inner race, pressing the hub, tightening the axle bolt.

1. Lift rear of car and remove wheels

2. Remove rear muffler mount bolts (4 total), exhaust will hang to clear sway bar and axle later

3. Remove rear sway bar entirely. It'll come out, just fool with it. You'll have to bend the end links a bit to get it through, but they're rubber so do it.
- Bolts on the suspension arm are 13mm on bottom and 17mm on top. The bolts on rubber bushings are 13mm both sides.

4. Remove brake calipers (2 guide pins) and hang to side. Lock the axle with allen wrenches in the brake disc (see step 6)

5. Remove the axle to differential bolts (6 each side) and support the axle with something (left use exhaust, right use a 5 gallon bucket upside down)

6. Unbend the 36mm nut's flange on the axle and break the nut free. Remove it entirely. You need at least a 24 inch breaker or other wrench for this. 1/2" drive minimum.

7. After removing the nut, place this tool over the hub and axle as shown. I got this from AutoZone. It's really made for their slide hammer, but I had a bolt from an arm puller that happened to fit. It's a 5/8"-18 thread I believe.

8. Make sure the axle will not get jammed up under the car. Start turning that center bolt. Crank it down hard. I had the wrong kind of bolt (flat tip), so I was probably putting 180 ft*lbs on my wrench to turn it. To break the axle free, if it's not moving, hit the bolt with a large sledge. I used a 10 lb sledge 3-4 times. After that, keep turning. The axle will make a pop sound every time it moves about a millimeter. It'll slowly come out.

9. Now that the axle is out, you can start to remove the hub. So, remove the caliper carrier (2 16mm bolts) and the brake disc. Remove the snap ring with snap ring pliers.

10. Now, reinstall the adapter onto the hub with 3 lug bolts. Screw in the slide hammer to the center threading. Now slam the hammer pretty much as hard as you can away from the car. The best way is to stand over the slide (straddling it) and move the hammer with both hands. It'll come off after 5-10 hits if you're not a pussy.

11. Now to remove the bearing. Set up the HF tool as shown. Use the largest plate that will fit on the back of the bearing and use the largest cylinder on the outside to catch it. I opted to orient the bolt the way shown, because the back side gets pulled in with the bearing. If you do the other way, your wrench won't reach after a certain point.

I opted to hold the other wrench with my jack like this on the left side. On the right, I just let it push on one of the suspension arms.

12. Do not touch the hub yet. Go ahead and clean the inner surface of the sleeve and prepare to install the new bearing. Use two plates for this. One on the back side that's larger than the hole, and the other on the face of the bearing. Choose the one closest to the bearing's outer diameter, but not larger.


If it's not clear, I ****ed up and pressed the hub in and forgot the snap ring. I had to buy a new bearing so I could drive home. Now I have a cheap Chinese POS bearing in the left side. Don't be me! I'll have to do this again in < 1 year now. I think you can even see the lack of snap ring in the next image.

14. Now that you remembered to install the snap ring, you can work with the hub. Remove the inner race by cutting it with a dremel cutoff wheel or similar. Get as close as you can to the surface of the hub, and then hit it with a good chisel. WEAR SAFETY GLASSES! The race is almost as hard if not harder than your POS chisel you had lying around. A piece of mine shot me in the wrist and drew blood. Hold the hub in a vise and protect the hub with a couple layers of a rag.

15. Press in the hub with the HF tool. This time, on the back side, use a plate that fits so you can support the inner bearing race. USE THE FLAT SIDE. This is very important. If you do not support the inner race, you will screw up the bearing. For the flange side, use the smallest adapter in the kit and put the flat side facing out.

(Sorry for the blurry images, my hands were shaking from fatigue)

16. Okay the hub is in and the job's pretty much done right? Wrong. You still have to get the axle in you moron. So after you have cleaned the splines for an hour with every means possible, go ahead and insert it. It's not going to go in all the way. What I did was use a long thin plank of wood and a 3 lb sledge to hit the back surface of the axle and slowly push it in. Do this until you can thread the new nut.

17. I'm not going to tell you how to put every thing back. The axle to diff bolts suck. Torque everything properly. That's all. Don't forget to bend the axle bolt's flange for safety. I used a 3lb sledge and a punch.

I have a dream that one day our children will live in a
nation where they will not be judged by the color of
their skin but by the color of their coolant.

Last edited by WDE46; 02-04-2014 at 12:32 PM.
WDE46 is offline   Reply With Quote