TheMilli

Vehicle: C300 4MATIC Sport

I'm new here but I've searched the threads up and down today trying to be sure of a question about rear suspension setup.

I just did pads and rotors on all 4 this past weekend and while under the car I noticed these arms in the rear. At first I thought maybe they were designed this way but I noticed both left and right had a different amount of bend to them so I assumed they had to be broken.

I'm almost positive I know what part to purchase but just want to be sure because I've seen this part called 3 different things...

On MB parts it's called the track bar. But when I cross ref the part # on other sites it's coming up with thrust arm/control arm/trailing arm. I'm getting new tires in a few days and wanna make sure I get it done before then. Thanks in advance!

TimC300

I call them thrust arms. Left and right are the same part #s and interchangeable. The other control arms are usually left and right only, different part #s for each.

When you replace them the Mercedes manual says to rethread the bolt holes in the cover plates going into the subframe, something about needing to clean out the old thread locker to be able to torque the bolts back properly. I have a set im wanting to replace in mine due to worn bushings.

TimC300

I'll attach where it says to rethread the bolt holes. Also the torque specs for the thrust arm.


The stop plates (2) have to be removed and holes for the bolts (1a) recut and blown out.


And torque the thrust arm nuts with the vehicle at ride height.



heres the tool part# if you need to replace the bushing in the carrier.

TheMilli

Thank you! I might as well do the bushing since I’ll have access to them anyways so thanks for the heads up!

TimC300

I noticed it looks like the plastic covers is missing also. Theres a top and bottom cover that snap together. I also noticed the thrust arm part # is updated to a 205 #, they should all be the same and fit.

TimC300

And if you dont have one you will need an M12 triple square socket for the bolt. I bought this one and its been holding up well after a few uses .




Heres a good video showing the replacement. Posted the wrong one originally.

TheMilli

I just got everything ordered last night and will be doing the job this Wednesday/Thursday. Thanks again for all the help and links it was more than I could of asked for!!

TheMilli

Do you happen to have the dimensions for the bolts on the stop plate(1a)?

TimC300

Got lucky and the size is listed in the parts diagram.

The bolts are expensive, around $12 at the Mercedes dealer. I bought a set of new stop plates since mine are rusting and will probably pick up a set of new bolts while I'm at it. Mines more of a preventative maintenance so not in a rush to do it.

Combination bolt # 0019901103 M12 x 1.5 x 135.5

TimC300

Heres the diagram for the bushings (50) if needed: