W210 / S210 estate rear suspension noise...has anyone ever fixed this?

[carswaps]

Hi all,

I,ve recently bought got a late 2003 E320 CDi estate (W210 I think or is the S210 the estate?)
Anyway have the usual clonk/thud from the rear suspension (its worse on the N/S)
I have changed both anti roll bar links - still the same , Both Shock top rubbers - still the same.
Just had the rear front subframe bushes done and its still the same!
Both rear shockers look good with no leaks and all the other arms bushes also look ok with no apparent movement.
I am thinking of replacing the spheres next but from the sound of the noise I,m sure it won't cure it?
The noise does seem to be right at the top of the shocks? could it be the spheres?
Any ideas guys? seems all W210 estates suffer with this at sometime so I,m sure someone must have fixed it?
Thanks for any advice.
Steve

 

[abecketts]

Might it be that the springs are broken, our e240 estate had that problem with "clonking" and both springs were u/s

 

[carswaps]

Might it be that the springs are broken, our e240 estate had that problem with "clonking" and both springs were u/s

I have had a look at the springs and can't see anything wrong with them but I'll have another look thanks

 

[V12]

Shocks are the main culprit.

 

[Lyserman]

I'm with V12 on this.
My S203 had an annoying clonk and renewing the ARB, associated bushes and bits did not cure it. I could find no play in the suspension bushes and despite the rear shocks looking okay I renewed both of them and that cured the annoying noise.

 

[renault12ts]

I'm with V12 on this.
My S203 had an annoying clonk and renewing the ARB, associated bushes and bits did not cure it. I could find no play in the suspension bushes and despite the rear shocks looking okay I renewed both of them and that cured the annoying noise.

Except on the 210 they aren't shocks but hydraulic struts, which cost a fortune. More likely to be the spheres.

 

[V12]

Bad spheres give a very hard and bouncy ride...

 

[carswaps]

It does feel a little hard at the back.
Would replacing the spheres stop the clonking though?
I,m wondering about getting the saloon bottom arms, springs and using normal shocks, deleting the self leveling system all together.
Cheapest I have seen the self level shocks for is about £250 each then the spheres at £70 each...it all adds up.

 

[Dieselman]

It does feel a little hard at the back.
Would replacing the spheres stop the clonking though?

Cheapest I have seen the self level shocks for is about £250 each then the spheres at £70 each...it all adds up.

The spheres probably will stop the knocking if they are going flat. As the gas pressure reduces the ram cant respond as quickly to the wheel movement so knocks.

Try Wunderpartz or euromerc for spheres.

 

[carswaps]

Thanks Dieselman!

Just a quick update, I had to go out in it today with 4 x adults in it and the clonking was greatly reduced, infact almost gone!
So with the suspension loaded almost curing the problem does this still point to the spheres?
Many thanks Steve

 

[ItalianTuneUp]

Bad spheres give a very hard and bouncy ride...

Could this cause a bouncy ride in a w220 like ours too? If not, what is main culprit? I'm getting quite a lot of bouncyness from back, and body roll.

 

[V12]

Could this cause a bouncy ride in a w220 like ours too? If not, what is main culprit? I'm getting quite a lot of bouncyness from back, and body roll.

No. There are a few possible causes depending on how bad it is. If it is almost rock solid then it may be in a "safe mode" where it locks the shocks and doesn't allow any air in or out. This is usually accompanied with a red warning in the dash cluster.

Apart from that, rough ride with airmatic usually means the shocks/struts are past their best.

 

[V12]

Thanks Dieselman!

Just a quick update, I had to go out in it today with 4 x adults in it and the clonking was greatly reduced, infact almost gone!
So with the suspension loaded almost curing the problem does this still point to the spheres?
Many thanks Steve

If the bouncy effect is severely altered with weight then it is more likely to point to your struts than your spheres.

With bad struts you will get clonking and rough ride. Worn spheres is much more of a bounce / oscillation.

Most people who have dealt with any hydraulic suspension would be able to tell from a drive of the car.

Keep in mind that your strut effectively replaces a conventional spring and the sphere is the replacement for a shock absorber.

 

[Dieselman]

Keep in mind that your strut effectively replaces a conventional spring and the sphere is the replacement for a shock absorber.

The strut is just a ram, the sphere is the spring.

 

[renault12ts]

...and the spring is a ...spring?

 

[V12]

The strut is just a ram, the sphere is the spring.

The strut supports the weight in the same way a coil spring does.

The sphere smooths the travel in the same way a shock absorber does.

What am I missing?

The metal coil spring is still there on a S210 but theoretically the system could work without it?

 

[Charles Morgan]

I had the same on mine.

It needed new spheres and new shocks/struts. When the spheres had been done it still went ker clunk over bumps. Loading is going to reduce the rebound on the shocks.

When sorted it was ok, but nothing like a Citroen.

 

[Dieselman]

The strut supports the weight in the same way a coil spring does.

The sphere smooths the travel in the same way a shock absorber does.

What am I missing?

The strut is just a hydraulic ram to connect wheel movement to the sphere by moving the oil. The sphere is the spring, offering both support and movement.

Hydropneumatic suspension.

Was ist die Hydropneumatik? - YouTube



and





[YOUTUBE]Tomy9qPIsaM[/YOUTUBE]

 

[V12]

Yeah, I understand how it works and my comparison is over simplified for sure. Its just for the purpose of troubleshooting.

For example if a strut seal is leaking the system will lose fluid and sag just like if a spring breaks.

From what I understand when the sphere ages the internal membrane becomes stiff and prevents hydraulic fluid passing to/from the strut at all or in a smooth manner. In extreme cases the strut can become 'locked' and the suspension so stiff that it reacts violently to any rough surfaces.

 

[Dieselman]

From what I understand when the sphere ages the internal membrane becomes stiff and prevents hydraulic fluid passing to/from the strut at all or in a smooth manner. In extreme cases the strut can become 'locked' and the suspension so stiff that it reacts violently to any rough surfaces.

As the sphere loses gas it fills more and more with fluid as the membrane retreats. This gives a stiffer ride until eventually either all gas pressure is lost or, more commonly, the membrane ruptures.
At that point the sphere fills with fluid and all suspension movement is lost.