My W123 euro TD sways excessively in the back at speed, and with any load in back. A little wind or slope in the road and the steering corrections I make can amplify and get real uncomfortable.

I'm looking at:
Slop in steering box, but my 240D had slop in the box and was driveable at speed,with a 616 in the trunk.

Sway bar- I heard the TD rear sway bar is different from the sedan. Mine is 1/2", same with a TD owner I checked with. I heard of a 19mm / 3/4" rear sway bar. Does anyone else know?

Sway bar links: Gotta check this out.

Shocks: gotta check these

Springs: gotta check these.

Any ideas or other experiences?

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

Swaying would usually be interpreted as body roll.
Steering corrections would be associated with yawing.

Can you clarify/expand on what you are experiencing?

SLS rear shocks seldom fail and they would not cause excessive swaying. Sway bar links are cheap and they are the most likely cause.

Yaw/roll couple, I think. In a plane, I think it's called dutch roll. If I correct by steering right to maintain a lane, the body roll left and it feels like it pulls right a bit, so I have to make the initial correction mild, or make the second such that I don't pump the oscillation and make it worse. Slowing down below 50-55 helps, but not always a good place to do it. Because I took flight dynamics in school instead of car dynamics, I would say that the i'm dealing with a pilot induced oscillation.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

My wagon was dangerous on the road when I first got it. Thought thats just how they were. Not really fun in a windy situation.

Rear differential mount, subframe mounts, and bushings on the rear control arms made it a very tight ride.

I give much of that credit to the subframe mounts above all.

__________________

There is no truth in what you heard. All wagons came with a 13mm rear sway bar.


.

__________________
1983 123.133 California
- GreaseCar Veg System

Interesting that you phrased things in these terms; it's familiar territory.
In Dutch Roll, yawing and rolling are coupled but out of phase in varying degrees, as opposed to coordinated aileron rolls, where yaw and roll are in phase. The Dutch Roll tendency of any given aircraft is usually considered to be design induced, rather than pilot induced.

In the situation at hand, el piloto may provide the initial displacement, but the vehicle design, when all is right, will promptly dampen any oscillation.

In addition to the above mentioned shocks, sway bar links, subframe mounts, and trailing arm bushings, the motion described may also be caused by tires whose sidewall construction/stiffness is poor. Raising tire pressure can mitigate some of the effects, but not all.

Most of the time el Piloto has most of the sky to do 'hands off stable'

>tires< Duh. They are new, but they do look soft.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

19 mm would be enormous for a rear sway even in a race car. I vote for sway bar linkage bushings.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Thank you people. I think I am saving trips and money by asking.

increase from 30->35 psi in back helps. It still looks saggy- it sits with negative camber. SLS may need some love.

sway bar- 1 link snug, the other a little loose, both intact tho.
dia, thanks for the knows people.
sway bar bushings- hadn't thought of it, thanks, I will check.

Subframe and rear lca bushings, thanks I hadn't thought of them. Is it a hard job Frank? I didn't see it in the wiki. I wouldn't be surprised to find an adverse roll/steer couple here if I made sense of the geometry.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

I wouldn't ignore the accumulators. Mine were of an unknown age. The SLS valve was rebuilt and the accumulators replaced. Did wonders for the back end waggle at higher speed. Plus the ride is much better at low speed.

The accumulators are easy to check. Loosen the relief valve on the height control valve to relief the pressure from the system. Close the valve once the pressure has been relieved. Remove the fluid tube from each accumulator and using the eraser end of a new pencil gently push the eraser end into the accumulator. If you feel resistance the accumulator is OK. If the pencil goes straight through the diaphram in the accumulator has ruptured.

The SLS system is self bleeding. After the fluid tubes have been replaced, start the engine and allow the system to bleed itself (much like a power steering system).

Go down the road, everyday transportation, grocery getters have their steering and suspension geometry laid out so that all chassis motions result in an understeer condition. The manufacturer's legal departments, and insurers insist on it.

The suggestions that you tidy up the SLS components, and the sway bar links & bushings, is the correct first step. That will result in tight roll control, and the chassis can be set to the proper ride height.

If the trailing arm bushings are so worn that handling is affected, there is likely to be quite a bit of thumping and clunking also.