[Carolina28]

My 86 300SE has been making a knocking sound when driving over ripples or uneven road. I was told that it is probably a large bushing on the front passenger side. I called my local repair shop and they diagnosed it without even seeing it. Said it would be $300 fix for the one bushing, and to align the wheels.

Is this a common problem with the older W126 like mine?

 

[500MPL]

Please be more descriptive as to the location that the noise is coming from. These cars have particular noises related to different areas of the car.

Regards,

 

[Carolina28]

The sound is coming from the front passenger side wheel well. I though it was the shock. Mostly while going over uneven pavement or rippled pavement. You can feel it in the steering wheel when it is making the sound.

 

[500MPL]

Check the ball joints and the tie rod ends. Also check the upper and lower control arms for wear.

Regards,

 

[MBL87560SEC]

Hi Carolina,

It sounds to me as if you are describing the brake support joint / caster bucket. here's a write up on it with some pics too. Additionally, the subject is covered extensively in the archives....

http://www.mbnz.org/forums/forums/thread-view.asp?tid=1181461&posts=13&hl=caster

You ask if it is a common W126 issue. Our cars are older, so yes I think there are quite a few on the road today that have support joints needing replacement.. wear/ripped boot etc.

Just yesterday evening, I had the pleasure of poking around underneath someone else's 560SEC, while armed with a really good flashlight. I found both joints had ripped boots & needed replacement.

Cheers, MBL

 

[blnk124]

its good to know though that most of these parts only crapped out after 15 years.

 

[Cheelyv]

Hi,
I changed the bushings and bearing in my brake support bracket a few months ago. The bushings are easy to press in and out on a press. Dishwashing soap works good as a lube.
The bearing was more difficult and required more skill and patience.
You can expect to see some rust and crap in the bracket once you get the bearing out. I have heard from several sources that say do not scour clean it.
Just clean it very lightly & barely enough to get the new bearing in.
Also, the 3 hex bolts that holds the cover on maybe extremly tight. Be careful not to round it out or snap it off.
Measuring the guide rod before disconnecting from the bearing is a good idea. However, you will still need to get an alignment.
Here are a few pics:

 

[mramay]

I've also done a set of dogbones along with new brake thrust rod bearings recently. Not a particularly difficult DIY job.

I used silicone grease as the lubricating agent on the rubber bits and the picture shows a home made press using some 1/2" all thread.

If you have bad lower ball joints, those also are somewhat of a DIY job - I took out my spindles and went to the local Mercedes dealer to have the ball joint pressed back in. I took out the old ones with a 2-pound hammer, but the dealer had the special adapter to press the new pieces back in.

 

[Carolina28]

thanks for all the pics, you guys have really helped me out!