[dennisspeaks]

I am looking at doing this myself, harbor freight has this tool, sent me a coupon can get it for $33. Will it work on MB? Ball Joint Press Kit

 

[Noodles]

Just make sure the receiver tubes are going to fit. You will have to measure the outer diameter of the ball joint and make sure that the inner diameter of the receiver of one of those three is a close match.

 

[mushu326]

bump on the part number of the ball joint. Thanks!

 

[mushu326]

For philipk2003, I saw that the parts that you bought are made by Hamburg Technic from Germany. How's the quality on those parts?

 

[Noodles]

Please read my post about them here. They are about as bad as Chinese clones. In fact
they really are Chinese and Indian parts with horrible quality control.
http://www.benzworld.org/forums/w163-m-class/1606758-best-place-buy-shocks-brakes.html

 

[dorenhagen]

There are three parts pictured!

Shown at the beginning of thread are three parts:

Control arm
Ball joint
Unspecified large rubber part​

What is the third unspecified large rubber part? Thanks.

 

[dorenhagen]

How long?

How long did each side take? Thank you.

 

[isstay]

Shown at the beginning of thread are three parts:
Control arm
Ball joint
Unspecified large rubber part
What is the third unspecified large rubber part? Thanks.

It is lower control arm bushing. What is shown is not control arm, it is torsion arm.

 

[dorenhagen]

Isstay, thank you. I wonder why he didn't mention the control arm bushing in his write up?

Do you have any idea how long this job will take? I replaced the control arm on the offending side with the knocking noise persisting. Next I'm going to do this job.

It is called a control arm on the parts web sites I've visited. I don't doubt that your terminology is more precise. I can't find a schematic of the W211 suspension with labeled parts!

Thanks for your response.

 

[isstay]

I do not know how long it is takes, but I can estimate hour to two hours depending on your mechanical skills and equipment you have. Each arm has a nut on one side and bolt passing through on other. You have to align new bushing against old one and marked it before extracting old one in order to install the new one correctly. They have elliptical opening w/ridges for alignment bolts.
Back to the knock you have – most likely is it from lower control arm or so called spring control arm ball joint (#20).

 

[dorenhagen]

Isstay,

Yes, that is precisely correct! I lifted the car and was able to isolate noise to that part. Should I replace tension arm with ball joint too? Will the new parts fail as soon as the old? I sure hope not.

Thanks again for your time and valuable input.

Doren

 

[Noodles]

That really depends on road conditions and driving style.

 

[isstay]

MB updated the design of the lower ball joint and should last longer. New part has “I” like mark on the bottom. You can replace torsion arms too and will improve any camber issues.

 

[dorenhagen]

Replaced control arm with ball joint (#140 in diagram on previous page) which eliminated completely the knocking rattle over gravel roads and small bumps. I did not replace the ball joint (#20 in diagram on previous page) since I was told it was good. Suspension is once again rock solid. The removed part clearly and obviously had failed.

I was told this was obvious when the suspension was examined both sprung as well as unsprung. My mechanic told me the best way to evaluate any suspension element is when the car is sprung (normal weight on all suspension elements). I had several very good shops look at this and none were able to diagnose much less isolate the problem.

Take home lesson (and please feel free to correct me): carefully check all suspension elements with the weight of the car normally deployed on the suspension. A good visual examination with vigorous attempts to move each component will reveal the offending part which has failed.

 

[isstay]

The best way to check suspension components for me is w/car weight supported by lower control arm instead the tire. This way you can rotate the wheel and move the spindle w/metal bar up and down when trying to isolate the problem, or even remove the wheel and have better access to all suspension components while still under full weight load. As of torsion arm, you can easy isolate the problem just grabbing it by hand and twisting it, or moving it up and down.

 

[N8T]

I sure hope someone here can help. My question is regarding the original post and changing the control arm. I don't want to get my car in the air then go get the tool I need. What tool do I use to remove the control arm from the frame of the car? Is it a torx or nut? can someone reply with the type and size and if there are any special instructions on that side of the control arm. The ball joint side seems pretty straight forward.

 

[Werkstattmeister]

21mm wrench and socket. Do not twist the bolt, only the nut. The bolt has two grooves that engage in ridges on the inside of the torque struts shown in the OP's first picture. The control arm is the part that the bottom of the shock and the sway bar link attach to and supports the weight of the car. The torque strut prevents fore and aft movement of the control arm and is used to adjust the caster via the special bolt.

Mark the orientation of the bolt head and try to determine which way the torque strut is offset relative to the bolt so you can maintain the original alignment during reassembly. Also, measure the height of the ball joint end of the original torque strut before you loosen the nut and bolt. When you reinstall, match the height and tighten the nut. This will approximate the orientation of the strut when the car is on the ground so you don't preload the rubber bushing. As I recall, the torque is 80NM then 120 degrees of additional rotation for the nut. The ball joint is torqued to 50NM then 60 degrees.

Edit 9-12-12: The measurements I mentioned above are performed without the strut attached to the steering knuckle. Only the bushing end installed and the ball joint end free of any attachments. M

 

[isstay]

Bolts w/grooves are for alignment and most likely not installed on the car w/o previous alignment problems, thus the original bolt will fit in only between the bushings grooves, still do not turn the bolt to prevent damage to the bushing ridges. Never tighten completely any suspension bolts and nuts until you put the car in driving position (sitting on the wheels or supported w/jack stands under the lower control arm, thus simulating driving position).

 

[MemphisFil]

Hi Isstay,
Just did my left control arm. I did not notice grooves on the bolt. I did see the ridges inside the bushing. The bolt went in well and I did not tighten the nut under load. What is the consequence of these things if any? Thanks.

 

[isstay]

Hi Isstay,
Just did my left control arm. I did not notice grooves on the bolt. I did see the ridges inside the bushing. The bolt went in well and I did not tighten the nut under load. What is the consequence of these things if any? Thanks.

Premature bushing failures because when your car is raised suspension components are pushed down by the spring. If you tighten the bolt and lower the car, rubber part of the bushing gets under constant tension when in working position.