I've been meaning to post this procedure for a while now in hopes of preventing others from enduring the headaches I ran into when replacing the rear hub. Amazingly I wasn't able to find a single post anywhere outlining the procedures and various roadblocks. Be forewarned, this is not a task that falls in the easy category. This is an arduous task without the benefit of a shop. You'll definitely understand why the shop labor costs are so high for this job if you attempt it yourself.

1) Apply the parking brake

2). Remove wheel from vehicle.

3) Remove the 30mm 12 pt axle nut. There is a metal stake that is part of the nut which must be bent outwards to allow the nut to rotate. The nut is torqued to 300lbs, so a breaker bar alone is insufficient. I placed the 6 foot handle from my floor jack over a 1/2 inch breaker bar to gain the increased leverage necessary to successfully break the nut free. I attached the socket with the breaker in the 5 O'clock position then squatted down with both hand on the bar and used my legs to stand straight up and that was sufficient to break the nut free.

4) Release the parking brake.

5) Remove the brake caliper.

6) Remove the brake caliper mount. Be aware that the 2 bolts are a non standard size, 18mm and are highly torqued.

7) Remove the brake rotor retaining screw and the remove the rotor.

7) disassemble the parkin brake shoes.

7) Remove the 4 of the 5 bolts which connect the lower control arm and multilinks to the hub and then remove those bolts. Leave the bolt to the lower control arm in place and instead disconnect the lower control arm bolt nearest the differential. You'll save yourself aot of trouble by removing the lower control arm still attached to the hub and then remove it once the hub assembly is off the car.

8) Remove the wheel speed sensor. It is secure by one torx bolt on the rear topside of the hub.

9) Remove the bolt securing the shock to the lower control arm. ( it's easier to proceed if you now remove the rear strut completely as it provides more unobstructed room to work but it isn't completely necessary to do so.)

10) Now you are able to remove the hub with the axle still attached by simply pulling on it. It will require a bit of strength, so keep pulling until you feel it pop loose.

11) With the hub assembly, axle, and lower control arm now freed from the vehicle, locate the parking cable plastic dowel on the rear of the hub and pull it out. It is snuggly for and will require a set of vise grips to be attached to it and turn it back and forth as you pull on it. Once the parking cable dowel is out, it'll release enough tension on the cable to more easily detached the parking cable. On the outside of the hub the mechanism which was previously secured between the top of the 2 parking brake shoes will now be dangling freely. Pull that mechanism out until you are able to open it up to a horizontal position. You'll then see a 3mm metal dowel at the end of the cable which at first will seem permanently attached. It is not. Simply take something the size of a ball point pen tip and press on that metal dowel. It simply pops right out and release the parking brake cable.

12) Now with the hub/axle assembly fully removed from the vehicle you can remove the axle from the hub with the aid of hub removal tool. I'll attach a link to the one I used below.

13) Now the not so fun part, removing the lower control arm from the hub. There is a metal bushing insert on the front of the hub where the lower control arm attaches to the hub. It protrudes out of the hub about 1-2mm. There is also a metal dowel through the center of the bushing of the lower control arm. That is what causes such a fight when trying to remove the lower control arm from the hub. This is why it's easier to remove the lower control arm with the hub because now you have much more room to use pry tools to break the control arm loose. When reinstalling the new hub assembly it's easiest to use a metal file and file the protruding dowel down to the same level as the surface of the hub. It makes reinstalling the lower control arm a much more reasonable feat as it'll simply then just slide into place on the hub.

 

Why did you have to remove the hub?

Excellent write up. I will keep the link.

 

The torsion link which connects to the frame to the front lower portion of the hub fractured and when it let loose it snapped the lower control arm in half. They say a picture is worth a thousand words, so I'll attach pics of the failure point on the hub that fractured..

 

Thanks for the guide. A couple of things to add. That 'bushing' that you show remaining on the hub from the broken control arm is actually a cylindrical ball joint. They tend to wear and increase negative camber. These are heavy cars and love to eat ball joints front and rear. I made a press out of a bolt, nut, and washers to press that sliding bushing back flush. That is probably the biggest hang up on the job because you think that the control arm should go back in the slot you removed it from.

 

Yep. Trying to remove the lower control arm with pry tools whilst still on the vehicle is an insane proposition because no literature clues you into the fact that that cylindrical ball joint that you describe is secured by that protruding dowel. I'd have never figured it out on my own and feel so lucky that one Mercedes tech posted about it's existence. With that little bit of knowledge I knew it would be an effort in futility to try to hammer a new lower control arm back into place. Hopefully now others will now know why their efforts to install a new lower control arm into the hub seemed so impossible. Not even worth the effort to try. And considering that we are at the juncture where R230's are at an age where most folks will choose deleting ABC in favor of Coilovers, it's imperative that folks NOT attempt to disconnect the lower control arm at the hub but instead ONLY disconnect the lower control arm at the end nearest the differential. Either file down the dowel, or fashion a press as you did and save yourself a lot of needless heartache! But if lower control arm replacement isn't nxecesaary for your fix, then NEVER attempt disconnecting the control arm at the hub. Thanx for adding your solution. I don't wish that attempt on anyone!