Is it possible to tell whether the suspension needs renewing?

[oscarisapc]

Is it possible to tell whether the suspension needs renewing? I’ve read about “tired” suspension and some forums recommend renewing shock absorbers at around 12 years old to retain optimum performance, even if they are not obviously leaking or malfunctioning. Is there any way of telling whether shock absorbers are past their best without any visible failure signs such as leakage or bouncing? I have an 07 W209 CLK500 Sport with 60,000 miles and although I love the car, I would have thought handling would be sharper in what was sold as a powerful sports model. I’d like to know whether renewing all or part of the suspension to take it back to “as new” performance would improve its handling and if so how do I go about it, or is this just how it is? I don’t want it lowered or hardened.Thanks

 

[Yugguy]

Worn shocks can either be excessively stiff or excessively soft. When soft the car will bounce on the springs for longer.

 

[Salal]

Shock absorbers can usually be quite hard to tell when they are worn if they are not damaged in any other way such as leaks etc...

The bounce test that people do can show some indications but isn’t the most accurate but you can observe how well it absorbs the oscillations. Another good way to test them is to test them when they are removed as you can properly check them and how well they work but of course this isn’t very practical.

I tend to replaced my shocks from 80-120k miles depending on the car. Quite often if you have been driving a car for a while you may not realise the shocks are worn as they gradually wear slowly and you get used to it or adapt to it you may not notice over time. But when new shocks are fitted the difference can be quite significant.

Also worth getting the right shocks from MB for the least hassle as they are so many different types per model as they are sometimes reasonably priced. Or cross check the part number against after market OEM ones such as from Sachs or Febi Bilstein to get the right ones. Some cheaper brands are not really worth it and won’t keep their performance over time and may even be worse than your current ones.

 

[Codger49]

The handling of my 2007 CLK500, now at 100k, has been greatly improved by having new shocks front and rear plus new front springs and assorted bushes/arms/droplinks as found necessary on inspection.

 

[oscarisapc]

Thanks. I'm encouraged to read of the improvement to a CLK from a suspension renewal - mine has lower miles but is also a 2007. I've probably just got to bite the bullet and do as Codger49 has done and replace all the potentially worn parts. I estimate a cost of £1500 or so to be a lot cheaper than the depreciation on a newer new Merc. The rest of the car is great - it just needs to go round corners as well as it does in a straight line.

 

[Codger49]

PS Haven't we been here before?

CLK handling - can it be improved?

 

[Edd1968]

Some great points mentioned here and agree with all of them.
There are alot of suspension components all expected to move in synchro with each other and of one is worn or out of alignment that will upset the whole applecart.
I'm lucky enough to be able to compare back to back our 2 CLKs which have very different set ups. Mrs Edd1968's Avantgarde with 16" boots, Michelins and standard suspension, mine with the AMG sport package on Contisport 5s.
Hers still feels very sure-footed round the bends, soaks up alot more road undulations yet still has a good balance of sporty stiffness about it.
Mine, with its 18" wheels, stiffer lower springs and different damper rates feels very planted round the bends, never a hint of understeer. Yet the tyres soak up a surprisingly large amount of the road unevenness.
Lets not forget though that these were never intended at balls out track handling race cars, they're fast GT cars, theres always a compromise to have to live with.

... My penny's worth

 

[alabbasi]

Yep, take it to a 1/2 competent mechanic and he'll be able to tell you after he spends 10 mins with a floor jack and a crow bar.

 

[Gazwould]

With the common event these days of springs snapping I wouldn't hesitate to replace them along with the new dampers and any top mounts etc .

Eibach Pro kit springs on a Sport would only lower around 10mm but they're developed and engineered better and so will handle better with improved comfort .

A perfect partner is oe Bilstein B4 dampers .

 

[OneForTheRoad]

PS Haven't we been here before?

CLK handling - can it be improved?

must of done alot of reversing , the mileage has gone down .

 

[whitenemesis]

Just replace with coilovers from a reputable company, Bilsteins worked wonders on my 2005 S203

 

[grober]

There's often a misunderstanding about replacing suspension components " before their time" Its the idea that the money is somehow "wasted" The answer is ---"not entirely" ----- Assuming a projected service life of 100k and a linear wear rate for springs and shocks then replacing them at 60k means you are replacing components that are 60% worn anyway with new ones = 0% worn.

 

[oscarisapc]

Quick follow up. Thanks for the advice. I took the car into my normal indie who is of the "if it ain't broke don't fix" school, but he agreed to have it on the ramp and check it out. Nothing obvious with the shocks but what he did find was the front shock absorber mountings both seriously worn and these have now been replaced. No idea how long they had been like that or whether it could have been detected on the recent MOT, but anyway the car is greatly improved and once more fun to drive.