W124 - Front suspension knock/creak over bumps

[Vectrolosys]

Hello,

Since I bought my W124, I have found that the front suspension will knock slightly when going over either a series of rough road surfaces, or going over extreme bumps, such as speed humps.

Just wondering if anyone could shed some light on this before I buy the relevant parts and fit them.

My instincts say it's either the Wishbone (lower arm) or perhaps an anti roll bar droplink, if the car is equipped with a pair, though I am not certain it is.

Thanks in advance,

James

 

[normanr]

Hi James
I had that on the back of my car and it was the spring on the offside rear had broken.

This is a common fault with the Mercedes just jack the car up and check the springs they usually go on the bottoms.

 

[Dieselman]

It's probably the ARB links.
Have someone hold the roof rails and rock the car violently from side to side, this will test the ARB links as they compress and rebound.

 

[bolide]

If the front goes "doiing" over bumps then it's the front ARB bushes. If it creaks it's the balljoints. If you hear rattles on rough ground that's a typical W124 effect. I've never found the cause but think it could be the top mounts or in the steering gear. Broken springs don't seem to make a noise

Thumping from the rear over rough ground and drain covers is the leading bushes of the rear subframe

Nick Froome
www.w124.co.uk

 

[Ian B Walker]

If the front goes "doiing" over bumps then it's the front ARB bushes. If it creaks it's the balljoints. If you hear rattles on rough ground that's a typical W124 effect. I've never found the cause but think it could be the top mounts or in the steering gear. Broken springs don't seem to make a noise

Thumping from the rear over rough ground and drain covers is the leading bushes of the rear subframe

Nick Froome
www.w124.co.uk

And that Lady's and Gentlemen is the complete thumpology of a W124.

Good post Nick

 

[Vectrolosys]

If the front goes "doiing" over bumps then it's the front ARB bushes. If it creaks it's the balljoints. If you hear rattles on rough ground that's a typical W124 effect. I've never found the cause but think it could be the top mounts or in the steering gear. Broken springs don't seem to make a noise

Thumping from the rear over rough ground and drain covers is the leading bushes of the rear subframe

Nick Froome
www.w124.co.uk

Hello,

Many thanks for this, I had a feeling it could be the Anti-Rollbar bushes, these are (hopefully) relatively easy to replace, so I am going to start here I think, it's definately a clonk which occurs over bumps, as opposed to a creak. A friend with an E38 7 series has a similar issue, which I diagnosed as the nearside ARB link, you can physically grab and shake the link!!

Anyway, this has given me something to go on.

Thanks all for your assistance.

James

 

[kth286]

As per Bolide, it will likely be the wishbone bush/s.

There is are no ARB links on front suspension on 124.

What happens is that the front wishbone bush tends to seize and that makes the rear bush wear more and it is the rear bush you can hear knocking.

Test by bouncing the OS front suspension first, then the NS to compare.

IF the front bush is seized to the bolt that goes through it, the bolt will need to be cut off to get the wisbone away from the car frame.

 

[lukebowman551]

I decided to replace the ball joints, arb bushes and wishbone bushes. I started the job on thursday. Everything went well until it came to removing the last bolt. This was the bolt that holds the front nearside bush in. It has seized to the inside of the bush just like mentioned in this post. I have just ordered a recipricating saw (DeWalt DW303K) from ebay which hopefully will arrive mon or tues. Then i should be able to get on with removing and replacing the bushes and putting the whole thing back together.