W123 Ball joint replacement - PeachParts Mercedes-Benz Forum

RML · #1 06-04-2009, 11:51 PM

I need to replace the lower ball joint in my 85 300D. I have read over a lot of articles here about some of the problems one runs into, like the difficulty of removing the ball joint itself, but I have not run across a definitive DIY step by step sequence of what I need to do, start to finish.

I am replacing my discs and pads, finished the right and when I got to the left side I discovered the bad lower ball joint. I don't want to put it all back together now and take it to my indy to do, as I am so close and think I can tackle this. Can anyone describe the steps, in sequence, that I need to do to accomplish this task? I have the hub off, as well as the dust shield. I just don't want to start taking things apart that do not need to come apart, and especially don't want to damage anything in the process.

Thanks for any help on this project.

jt20 · #2 06-05-2009, 12:53 AM

Removing the spindle is your best bet if you do not have the correct tools.

It can be done without removing the spindle, but the spring will still need to be compressed and installation of the new BJ will be more challenging with the spindle on the car.

A rough outline:

Remove the caliper

Compress the spring

Remove the steering arm from the bottom of the knuckle / spindle

Remove the nut from the Lower BJ and use whatever means available to remove the lower control arm from the BJ. Here is where the correct tools will save time, suffering and extraneous damage to parts. Many would suggest removing the entire knuckle and bringing it somewhere, you then risk destroying the upper control arm BJ. (but it can be done w/o damage)

I am sure I am missing some details, the rest is subjective.

tangofox007 · #3 06-05-2009, 08:06 AM

The FSM calls for removing the steering knuckle and knocking the ball joint out with a hammer.

Deltacom · #4 06-05-2009, 08:27 AM

As J20 pointed out, having the correct tools makes all the difference.
Here as process in this vdeo that though is not a 123 the process is very similar. Piece of cake!

Douge · #5 06-05-2009, 08:40 AM

Quote:

Originally Posted by Deltacom

As J20 pointed out, having the correct tools makes all the difference.
Here as process in this vdeo that though is not a 123 the process is very similar. Piece of cake!

tangofox007 · #6 06-05-2009, 08:46 AM

Quote:

Originally Posted by Deltacom

Here as process in this vdeo that though is not a 123 the process is very similar.

The "similarity" might be subject to debate. For starters, there is no need to compress the spring on a W123, if the weight of the vehicle rests on the lower control arm and only the steering knuckle is to be removed. Secondly, the lower ball joint on a W123 is press fit into the steering knuckle, not the control arm. Thirdly, the W123 doesn't use a "split" attachment for the ball joint stud, so separation is not simply a matter of loosening a bolt.

dannym · #7 06-05-2009, 08:53 AM

If you haven't found a decent DIY then you haven't used the SEARCH function!

This was in the DIY section:
http://www.peachparts.com/Wikka/W124BallJoint

Found these using the SEARCH function:
http://www.peachparts.com/shopforum/showthread.php?t=231358&highlight=ball+joint&page=2

http://www.peachparts.com/shopforum/showthread.php?t=179284&highlight=ball+joints

http://www.peachparts.com/shopforum/showthread.php?t=225956&highlight=ball+joint&page=3

http://www.peachparts.com/shopforum/showthread.php?t=220450&highlight=ball+joint

Lots & lots of threads on this topic.
Make sure you use the proper tools.
The steering knuckle has to come out. I used this on the upper control arm joint:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=99849

Don't crush the nut, it has an allen keyway to hold it in place while tightening the locknut.

Use a pickle fork on the ball joint. With some serious blows from a 5lb sledgehammer. I had to grind down the pickle fork because it was hitting the inside of the steering knuckle. After that it worked fine.

Use a large socket to hammer it out and a AutoZone ball joint rental press to install the new one.

directions are all over the archives all you have to do is look.

Danny

jkubica · #8 06-05-2009, 09:28 AM

Quote:

Originally Posted by jt20

Removing the spindle is your best bet if you do not have the correct tools.

Remove the steering arm from the bottom of the knuckle / spindle

Remove the nut from the Lower BJ and use whatever means available to remove the lower control arm from the BJ. Here is where the correct tools will save time, suffering and extraneous damage to parts. Many would suggest removing the entire knuckle and bringing it somewhere, you then risk destroying the upper control arm BJ. (but it can be done w/o damage)

Hi

I had a rough time getting the ball joint loose from the lower control - nothing works until I got a free rental pittman arm puller from O'Reilly's.

Don't use a fork on the upper ball joint since it will mess up the boot and you will end up replacing the upper control arm. A screw type seperator will work without destroying the boot.

Once I had the spindle loose, I took it with LBJ still attached to a machine shop to have the old one pressed out and the new pressed in. It is not an easy job even with a ball joint press - unless you have the special Mercedes tool.

Good luck,

Joseph

toomany MBZ · #9 06-05-2009, 12:20 PM

I took mine to a shop, one of his workers swapped it out on the car, an experienced suspension mechanic can perform the procedure. They have, or in my case, can borrow, the necessary tools.

RML · #10 06-05-2009, 11:31 PM

Thanks for all of this feedback and info. I did come across a number of these ariticles but a lot of the info was about the SD rather than the D. The SD looks a little more complicated. I am going to pour over this stuff while I am waiting for the ball joint to come in. I may take the steering knuckle down to a local garage to have the BJ pressed in. My biggest concern was damaging he upper BJ, but with the right tool I think I'll give it a go.

tobybul · #11 06-05-2009, 11:45 PM

When I did mine on my D's. I took the spindle off with the balljoint and brought them to a NAPA that had a machine shop. They pressed out the old bj and pressed in the new bj, all for under $20.

I would not bother renting a BJ press.

You will need a BJ separator to pop off the BJ from the ??? . Something like the OTC 7315. I do not advise using a fork

. Trust me on this

.

whunter · #12 06-06-2009, 12:36 AM

The W123 and W126 lower ball joint replacment operation is the same.
The only variation is 1985 and later W126 have a wheel speed sensor you do NOT want to damage..

There is no reason to remove the spring for lower ball joint replacment, simply support the lower control arm, and do NOT remove the shock absorber while the knuckle is off..

Here is a thread with many good pictures you should read.

Lower Ball Joint Replacement Question
http://www.peachparts.com/shopforum/showthread.php?t=142212

Have a great day.

RML · #13 06-13-2009, 01:23 PM

OK, first of all, I am working on an '85 300D, not an SD. I have read through most all of the related posts here and this is where I am. I have the rotor and hub off, the caliper up and away, and the upper ball joint loosened so I can lower the steering knuckle away from the upper control arm. I borrowed a 3/4" ball joint remover to separate the upper ball joint. I have the lower control arm supported with a floor jack under the spring. I also have the nut removed from the lower ball joint. I want to take the steering knuckle/spindle off so I can take it to my mechanic and have the bad lower ball joint removed and the new one pressed in. I cannot get the spindle to drop down and off, as it seems that the shaft of the lower ball joint will not release from the lower control arm.

If I had a ball joint remover that was slightly larger than the 3/4" one I borrowed, it looks as though I could slip it around the ball joint shaft and push it out. Do I need to get a larger ball joint remover to do this or is there another way to release the ball joint from the lower control arm?

Thanks for any help on this last step.

jkubica · #14 06-13-2009, 05:28 PM

Quote:

Originally Posted by RML

OK, first of all, I am working on an '85 300D, not an SD. I have read through most all of the related posts here and this is where I am. I have the rotor and hub off, the caliper up and away, and the upper ball joint loosened so I can lower the steering knuckle away from the upper control arm. I borrowed a 3/4" ball joint remover to separate the upper ball joint. I have the lower control arm supported with a floor jack under the spring. I also have the nut removed from the lower ball joint. I want to take the steering knuckle/spindle off so I can take it to my mechanic and have the bad lower ball joint removed and the new one pressed in. I cannot get the spindle to drop down and off, as it seems that the shaft of the lower ball joint will not release from the lower control arm.

If I had a ball joint remover that was slightly larger than the 3/4" one I borrowed, it looks as though I could slip it around the ball joint shaft and push it out. Do I need to get a larger ball joint remover to do this or is there another way to release the ball joint from the lower control arm?

Thanks for any help on this last step.

Like I said above, a free rental pittman arm puller did the job for me

kerry · #15 06-13-2009, 05:43 PM

Get a long pry bar--6-8'. Put it in a position to pry apart the ball joint and lower control arm. Then get a small sledge hammer and strike the surrounding portion of the lower control arm with it. It usually takes 3 or 4 blows. It's easier if you have a helper standing on the prybar. I have always found this pressure/shock method to be more effective than presses or pickle forks.