Confusion between "downward" and "upward" facing control arms
Thread Starter
Newbie
Joined: Apr 2018
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C230 Kompressor
Confusion between "downward" and "upward" facing control arms
My wife's 2005 Mercedes needs new control arms. I looked up in online auto parts and found out that there are two different types of control arms:
Front Lower Control Arms
-With upward facing ball joint
and
-With downward facing ball joint
I am confused between these two. Do I need to look at my wife's C230 suspension system to find out which one it has (upward or downward)??
Thanks -madmax
Front Lower Control Arms
-With upward facing ball joint
and
-With downward facing ball joint
I am confused between these two. Do I need to look at my wife's C230 suspension system to find out which one it has (upward or downward)??
Thanks -madmax
Member
Joined: May 2006
Posts: 102
Likes: 3
From: Vancouver, BC
2002 C240
If your C230 is RWD, they have both a lower and upper control arm. When looking online at the control arms the "lower control arms" will almost always be black color. The upper control arms are usually always silver in color.
So for the front suspension you have an upper control arm (silver) and lower control arm (black) for each side of the car.
So for the front suspension you have an upper control arm (silver) and lower control arm (black) for each side of the car.
Super Member
Joined: Oct 2013
Posts: 527
Likes: 20
From: Carolinas
2005 C230K SS
The upward or downward part refers to which direction the ball joint is mounted. One control arm ball joint mounts pointing down, the other one up. You need one of each. Reference thread #2 here for a similar setup... https://mbworld.org/forums/c32-amg-c...ntrol-arm.html
Usually the one facing up is black while the other is silver, as has been mentioned.
Usually the one facing up is black while the other is silver, as has been mentioned.
Newbie
Joined: Feb 2022
Posts: 10
Likes: 0
2009 c250 cdi
So what about the rear upper/lower control arms? has anyone looked at replacing the rubber bushes with spherical bearings?
And are you just using poly bushes for the lower pressed steel arms?
And are you just using poly bushes for the lower pressed steel arms?
Last edited by indigoskywalker; Feb 9, 2022 at 06:17 AM.
MBWorld Fanatic!
Joined: Dec 2003
Posts: 3,275
Likes: 236
From: BC, Canada
2003 C230K Coupe Orion Blue
Most people here just buy the arms with the rubber bushings already pressed in. Technically the arms can be purchased without the bushings, but I have only seen this part once ever in person.
There is a reason there are no spherical bushings for these parts. The angle of movement required is very low, and the upper arms (the ones that attach to the front part of the subframe) actually flex a bit when the steering angle is on the extreme ends.
The newer style (ie 204 PN) bushings are much improved over the original style. They've added a plate in the middle of the rubber to improve rotational stiffness. If anything I'm now finding that the ball joints at the knuckle end are the weak spot.
There is a reason there are no spherical bushings for these parts. The angle of movement required is very low, and the upper arms (the ones that attach to the front part of the subframe) actually flex a bit when the steering angle is on the extreme ends.
The newer style (ie 204 PN) bushings are much improved over the original style. They've added a plate in the middle of the rubber to improve rotational stiffness. If anything I'm now finding that the ball joints at the knuckle end are the weak spot.
