Their is a strange clunking coming from my front end, it has been doing this since late last year and I can't seem to find the bad part? So far I have done:
new shocks
new tie rods and center link
idler arm rebuilt
guide rod mounts

The clunk is strange it doesn't do it all of the time although the cold makes it occure more often. It usually does it as I am coming to the end of a stop say under 5mph, also if I am going down a steep driveway or apron it does it worse. Also it will clunk when I am going in reverse. I can feel the clunk in the brake peddal, it feels almost like the ABS is kicking on? Usually it will go clunk, clunk and I feel it in the peddal.

Now I have checked everything, it is all tight. The shop that did my alighnment commented on how tight the front end seems to be.

Any ideas? I suspect the upper control arms but I don't want to replace them at this time if I don't have to. ie no throwing $250 worth of parts at it hoping they fix something. I will do a complete front end rebuild later this year but I would like to fix this clunk before then.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Have you checked the front stabilizer mounts? I know that on my 124 the rubber was worn and even though it didn't look like it, they were and as a result each end of the bar banged the inner whhel axle area making the sounds you describe! BB

Sybill the SDL does a similar thing...clunks and then you can feel/hear the ABS run. I've already sprung for a set of upper control arms, lower bushings and ball joints that I'll install soon...I imagine that when I dig in there I'll be doing guide rod stuff too....

You might, get under the backend and pry on the trailing arm bushings. A couple of years ago when we bought Passion Flower, it had a serious clunk that felt like it was right under your feet when sitting in the driver's seat. I pried, poked and yanked on every piece of the front suspension and couldn't figure it out. We took it on the highway and the damned thing felt like it had a hinge installed in the middle....turned out that the outboard driver's side trailing arm bushing was totally shot...1/8" of play. After we fixed that, the handling improved (surprise) and the clunking under your feet ceased.

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Never a dull moment at Berry Hill Farm.

Yep, castor rod bushes for sure. Very common. quite simple to replace thankfully. How many miles on your 126?

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Andrew
300e 294,000mi
380sel 185,998mi
380se 309,980mi

Castor rod what? This is a W126 not a W124 or am I missing somthing?

I have an upper control arm that conects to the roll bar. Then their are bushings on the lower control arm, and one in the lower control arm that holds one end of the guide rod. The guide rod screws into a guide rod mount. The guide rod mount is a big aluminum L with two large grade 8 bolts that go through bushings and hold it to the frame.

Anyway, the engine mounts are also new, and I greased the front bearings last spring.

R Leo is the trailing arm bushing a subframe mount? I did those last fall.

I think we are using different names for the same things!

I have inspected my upper control arms a few times and they are tight, but the ball joint could possibly be lose I guess. Thats the only part that I think just maybe be causing the problem. It doesn't feel lose when I tug on it but maybe when loaded on the road it is? The lower ball joint is tight as can be.

I think my ABS acting up and that this is not a suspension problem. Why would a worn upper control arm cause the brake peddal to kick back like the ABS is kicking on? Is their a relay I could pull that would disable the ABS system?

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

No I have not checked the manual yet, I was getting to that. But the manual will only tell me how to replace parts.

I jacked the car up to check the suspension, and took the tire off so I could get in their better.

So I could put a pry bar in between the upper ball joint and see if their is a little play that way? I wouldn't want to damage the joint so I would use just a little force. I don't have a dial indicator though.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It is on SALE !

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=33675

I honestly cannot believe that the upper ball joints can be so bad that they exhibit a clunk. You would notice the steering being all over the place before they would get this bad. They normally fail by starting to squeak, not clunk. You can drive them in this squeaking mode for many miles, if you are not annoyed by it.

I'm a little confused by "castor rod bushings" as well. I don't understand this term on a W126.

I would additionally like some clarification of the "subframe bushings" on the front end of a W126. Are these bushings the ones that are used to hold the guide rod mount bracket to the frame? I presume that you changed these, Hattie, when you did the guide rod mount.

Hehe...the front end play in Sybill the SDL would be easier to measure with a wooden ruler.

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Never a dull moment at Berry Hill Farm.

I think 'castor rod' = guide rod.

__________________
Never a dull moment at Berry Hill Farm.

Ahhh..............Thanks Randy.

Looks like that SDL has some work for you, heh?

I prefer to think of it as a learning experience.

__________________
Never a dull moment at Berry Hill Farm.

Well, after you have become edumacated, you can saunter on up here and edumacate me on this one.

Here's a probability for ya'. Your sway bar bracket has probably rusted to the point of breaking. My mom's 420SEL did the same thing, I noticed by looking through the wheel well and seeing the bracket half sticking up in the air. You may have to remove the plastic guard, but check both of your sway bar brackets. Does the car have any sort of pull on braking?

Thanks
David

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2000 Honda Accord V6 137k miles

1972 300SEL 4.5 98k miles

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It has a thread on it for adjusting the castor on the front wheels. I'm not sure what they call it in the EPC. Trailing arms are in the rear suspension. ABS faults normaly groan and vibrate the pedal. I've never come across one that kicks the pedal back. First time for everything though!

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Andrew
300e 294,000mi
380sel 185,998mi
380se 309,980mi