C207 Suspension

[Robofyork]

Hi All.
Newbie to Merc’s. Just acquired an e250 coupe with a few niggles I’m working through.
Car drives great but has a slight knock from the front, both sides, only on small sharp sort of bumps. The damping seems real tight as if the suspension is kicking out when it feels a slight compression, weird.
Question is, what are the common failures on the front suspension? Is there a particular bush that’s susceptible to failing? It doesn’t sound like a ball joint so I’m assuming it’s one of the bushes.
Thanks

 

[SmartAmg]

Welcome, Rob.

 

[Robofyork]

Thanks pal. You went for the 350 then. I find mine quick enough but I bet they shift

 

[SmartAmg]

Thanks pal. You went for the 350 then. I find mine quick enough but I bet they shift

Yep, it does go a bit! Mines mapped, too, 300bhp & 714nm torque. Fantastic looking motor the C207

 

[markjay]

Welcome.

Typical knocking from front suspension on the W204:

- Hydrobushes (on the castor control arm)
- Drop links
- Strut top rubber bush
- Strut top bearing
- Broken spring(s)
- Tired damper(s)

Sorry I can't be more specific... on mine, I changed the hydrobushes, drop links, and top bushes (but not the bearings, or the dampers).

 

[Robofyork]

Yep, it does go a bit! Mines mapped, too, 300bhp & 714nm torque. Fantastic looking motor the C207

Beautiful things, treated myself after 3 years of sensible car ownership.

 

[Robofyork]

Welcome.

Typical knocking from front suspension on the W204:

- Hydrobushes (on the castor control arm)
- Drop links
- Strut top rubber bush
- Strut top bearing
- Broken spring(s)
- Tired damper(s)

Sorry I can be more specific... on mine, I changed the hydrobushes, drop links, and top bush (but not the bearings, or the dampers).

Cheers matey. Think I can rule out springs, drop links sound a bit different, but top rubber bushes or the hydro bushes sound about right. I’ve got the cd manual thing so will have look for a diagram.

 

[markjay]

The hydrobushes are cheap, but it's a pig of a job to replace them, and you need a press. I recommend replacing the control arm complete with hydrobush and ball joint. Lemforder are around £200 per side (it's a light alloy arm). In either case, the suspension geometry will need to be readjusted.

The strut top bush, bearing, and drop link can all be replaced in one go.

 

[Robofyork]

The hydrobushes are cheap, but it's a pig of a job to replace them, and you need a press. I recommend replacing the control arm complete with hydrobush and ball joint. Lemforder are around £200 per side (it's a light alloy arm). In either case, the suspension geometry will need to be readjusted.

The strut top bush, bearing, and drop link can all be replaced in one go.

I’ll probably look at doing the arms then as I don’t have access to a press. I take it the arms are relatively easy to get out?

 

[markjay]

I’ll probably look at doing the arms then as I don’t have access to a press. I take it the arms are relatively easy to get out?

Yes. And you'll need a ball joint splitter, but these are easy to get (and if the ball joint isn't seized you can usually remove it even without the splitter tool).

But remember that you'll need wheel alignment after that.

 

[markjay]

 

[markjay]

 

[Robofyork]

It might be cheaper to buy myself a used press by the time I've replaced all the bushes. I'm assuming it makes sense to replace both of those control arms in the picture while I'm at it? The ball joints seem OK, the noise I'm getting is a single clunk rather than a rattle so probably a bush worn or even too hard maybe. I'll price them up as bushes and as full arms. Cheers again

 

[markjay]

This is what I paid for the hydrobushes and dust covers (3 years ago):

 

[markjay]

That said... if I had to do it again, I would buy the whole arm:

Lemforder Suspension Arm | Euro Car Parts

Lemforder Suspension Arm at the lowest UK prices from Euro Car Parts UK’s No.1 for Car Accessories, Car Styling & Car Care. Buy today Online, In store or by Phone + Branches Nationwide – Next Day UK Free Delivery.

www.eurocarparts.com

 

[Robofyork]

Like wow. Would never have thought anything mercedes was that sort of money. I reckon a 6 or 12t press will cost me £100. Could be the way forward. Cheers

 

[markjay]

The alloy arms are considerably more expensive than metal ones.

As for the hydrobushes:

Delphi TD758W and TRW JBU619 are about a tenner each.

MB A2043331114 and Lemforder 35400 01 are around £20 each.

And don't forget the dust caps.

 

[markjay]

While your C207 has W204 underpinning, do verify the part numbers on EPC before ordering, I.e. don't just assume that the part numbers in my links are correct for your car (though they probably will be).