i have been noticing some extra vibration in the front right when i go over any significant bump. kind of a shudder-like sound. about a week ago i hit a pot hole and heard a distinct heavy thud in the same area. steering is tight, and handling is good otherwise, so the shudder has me thinking new shocks are in order. does that sound like the right diagnosis.

i should add i went back to the PO's maintanence records (dating from 1989-2002, about 100K to 230K) and there was no shock replacement noted. am i overdue anyway?

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1979 300TD wagon (non-turbo)
266,000+

The bilsteins last a very long time, but after a couple hundred thousand miles they are surely shot.

New shocks will transform your car and make you wonder why the heck you didn't do it sooner.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Yes, and an easy DIY

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83 SD

84 CD

I concur, if you have to ask yourself... it's time.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

The thud in the front when going over a bump could also be due to bad upper control arm bushings. I have the same thing going on w/ my car. It's on my list of.

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85 300D (California) 220k
03 Silverado 1500 Xcab Z-71 Guzzler 90k Real American steel(made in Canada)
03 Suburban 1500 4x2 Guzzler 170k Real American steel(made in Mexico)
Diamondback hybrid
Element skateboard(mileage unknown)

Good news for diesel owners...There's no such thing as cold...only the absence of heat!

"Beer is proof that God wants us to be Happy." Benjamin Franklin

"Possession....the King of sin." The Avett Brothers

Doesn't sound to me like front shocks. If your front shocks were shot (which might be the case as well), then you'd have a soft, boaty feel, it wouldn't handle well any unevenness of the surface, it might get bouncy as well (but if you don't know what new shocks feel like, you might have no point of comparison, new shocks make a huge difference in the way the car handles). Your symptoms sound more like upper balljoint/ control arm issues or possibly lower ball joint. Maybe just some bushings, if you're lucky. Does it make squeaky sounds when you turn the steering wheel extremely to one side? Lower ball joint is not really a DIY job. Upper control arm might be ok to do yourself, but not as easy as shocks.

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

I have never driven a 123 with bad shocks yet. Just my luck I imagine. The older gas cars would bottom out the front ends pretty easy with bad front shocks though. If yours are that bad a bounce test on the fender might be an appropiate test. Might even indicate another source of the noise for all I know.
New shocks are nice even if the old ones are only half bad. Adsit has them for 100 a pair or less. I would only buy normal blisteins regardless of price though.

I second this. Bilsteins are a must, and there you should get the "heavy duty" kind, not the "comfort"...I put them in my 85 123, there were KY in there (whatever the cheap white ones are called), the difference was incredible. So tight and great handling now. I recently put Billstein heavy duty in my wagon in the front, and it also made a nice difference. As John Allen says: the Billsteins act like a helping hand from underneath, making the car feel lighter and more precise at the same time. you can get them for around $80 a pop at www.*************** or at Rusty's. It's quite easy to do them.
But that noise of yours, I don't think it's the shocks.

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

I think I have experienced the effect the OP is talking about on the 240D that I used to have.

It is hard to describe. When you hit a pretty good pothole or other bump, you get an oscillation. Not so much a thud or bang, although that may be included in the initial hit. It feels more like the front end is being rung like a bell, but of course at a very low frequency. I also had a hard time determining if it was the front wheel or the rear.

The car departed on its own - but I had plans to replace the shocks. So I think you are on the right track.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

Thanks for the responses everyone.

Since I have no indication the shocks have ever been replaced, I think I'll start there. It is a little bouncy, but not too bad - but maybe that is due to one shock being shot and the other OK? But cgunderm, you are right, I have never had a car with bad shocks, so I am clueless as to how it should feel!

According to the records I have, the upper control arms were replaced at 155K. Would that indicate they should be ok? I'll do a visual check anyway, but what exactly should I be looking for that would tell me they are shot? And is this something that should be done immediately or will I survive another 1000 miles if I need new bushings? I should also add, that I have no sounds when turning the wheels, and handling overall is good. Just a little extra bounce and shudder.

So Bilsteins - Heavy Duty or Regular?

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1979 300TD wagon (non-turbo)
266,000+

To check UCA, you need to inspect rubber bushing at the inside top. Follow from upper ball joint. I had uneven wear on my tire, had a shop diagnose, they showed me where there was very little rubber left. Easier to see when on a lift. Yet, if they're new, well... Lower ball joints can be difficult. I replaced all four shocks with regs, before I knew better, ok. The best way I can describe, it felt as there were a pivot point in the middle of car at highway speeds. Bilstien shocks, many folks put HD's on front, regulars on rear.

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83 SD

84 CD

Before I had any work done to improve the handling of my `84 W123, I had this issue. Since I knew I wanted a total suspension rebuild all along, I just bought all the parts and had them installed. However, I did the Upper control arms myself, and that did not help the bump and chunk issue. After the Lower Control Arm Bushings were done, there was no more chunkiness- but I also needed new brake thrust arms and brackets. Those 2 things rectified the issue 100% and the car is as new (handling, of course). I would inspect the brake thrust arms and brackets and LCA bushings- uneven tread wear will indicate bad ball joints, clunking is not necessarily ball joint related.
I chose to use Bilstein HD's all around- now i don't need to ever worry about the shocks again as Bilstein has a lifetime warranty. This shock upgrade made a significant improvement in ride and handling and I would reccomend this upgrade strongly.

Just did a visual inspection of all the bushings, as well as feeling them for cracks or uneven wear. They seemed in good shape - no cracking or wear that I could tell. The rubber at the top of the shock mount (under the hood) is definitely shot, so a sure sign they have not been replaced, possible ever!
especially considering the rubber at the top mount of the shocks is definitely

What is the "brake thrust arm"? I am total noob, especially with front suspension. I use the performance products catalog to identify parts, its decent as a textbook.

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1979 300TD wagon (non-turbo)
266,000+

It was explained to me that this component is the Mercedes solution to an A arm in these cars. The thrust arm is he part that projects rearward into the subframe? and inserts into a box (bracket) that is bolted to the subframe. It takes the rearward force of braking. If this component is shot than there will be alot more noise. Of course, I really dont know what I am talking about here. I am jut repeating what my Indy told me.