Rear Weak Shock, Does It Affect The Ride Height?

[MrG 3]

on the rear of a 205, how exactly does the rear suspension actually work? For eg if one shock is week can this affect the ride height at all? I can see the anti roll bars running from one side to the other but I'm at a bit of a loss as to how it all actually works. There was a thread I'm sure that went into this but I can't find it.

 

Many thanks

[bouver 0]

on the rear of a 205, how exactly does the rear suspension actually work? For eg if one shock is week can this affect the ride height at all? I can see the anti roll bars running from one side to the other but I'm at a bit of a loss as to how it all actually works. There was a thread I'm sure that went into this but I can't find it.

 

Many thanks

 

 

There is something wrong if you can see the anti roll bar!

 

The bars you are probley talking about are the torsion bars. You can think of these as being like the coil springs on a McPhearson strut set up ( like the front of the car). The shocks or dampers as they are more accurately called control the movement of the rear trailing arms in that they 'damp' it.

 

The anti roll bar is located in the middle of the rear crossmember, it is splined and connected to the end plates, you can see these bolted to each trailing arm and they usually have a brake line bracket attached there too.

 

I hope that makes sence to you, PM me if you need any explaining.

[jimistdt 1]

 

 

Here's a simple drawing of the torsion bar beam. It's just as Bouver describes above, but hope this makes it easier to understand.

 

I doubt the damper alone would affect the ride height, as at rest the damper should be misdstroke, so unless it had failed altogether then the symptoms point to either a badly set beam when it's been rebuilt or a beam that is seizing due to failure of the bearings in the tube or the axle shafts are corroded so much they can no longer rotate.

 

It sounds like your best bet is to get it stripped and inspect the internals.

[MrG 3]

cheers all, that's great thanks, no it all seems fine on ours, its another that I queried. But after thinking about the rear set up it occured to me that I didn't know how the thing actually worked so what you've both described has helped a great deal. Thanks

[CosKev 16]

Rear shocks have altered the ride height slightly on mine for sure

 

Removed Spax crap things that did not return when you pressed them down

 

Fitted Konis which return back to fully extended on there own when pressed down and now the rear is slightly higher than it was with the Spax

[MrG 3]

that's interesting, we have spax nitrogen on this new 205 of ours and they're ok but not exactly brilliant.

[yeti-dj 7]

As the torsion bars are the spring and the dampers are oil filled if the spring at the end of its stroke doesnt have enough power to fully extend the damper then yes it will affect the ride height but it will affect it not matter what height the car starts at, if you raise the car 20mm the torsion bar will still have the same power as if you lower the car 20mm, follow me?

 

the power of the torsion bars never changes unless replaced with a thicker bar then you get a more powerful spring.

 

in the end yes your weaker damper will be easier to fully extend.

 

loving the drawing as well..

Edited July 18, 2010 by yeti-dj

[CosKev 16]

that's interesting, we have spax nitrogen on this new 205 of ours and they're ok but not exactly brilliant.

 

Mine handled lovely IMO on the Spax when new

 

But they did not last long

 

Mine were RSX adj,only running them on half hardness,but pass side one went very soft after circa 18 months of road use

 

When removed as I said you could compress them down and they stay compressed

 

The Konis I've fitted return to full length pretty quick after you fully compress them

 

Not sure why the two are different?????????

Edited July 18, 2010 by CosKev

[Rippthrough 98]

Different internal construction, some dampers simply aren't meant to come back out when you press them, and it shouldn't be used as an indicator of whether it's still damping properly or not.

[johnsimister 10]

Gas-filled dampers will automatically extend themselves because of the gas pressure inside. Non-gas, such as OE 205 dampers, won't. The gas pressure might give a fractional increase in ride height.

 

John