Brian:
Unless you are running downhill in the mountains with your foot
floored, you are very unlikely to test the handling limits of a 240 D.
Less body roll will overload the outside front tire and force it off
the rim, at which point the car will proceed, completely out of control
of the driver, on the tangent of the curve you are on. No steering, no
brakes, etc. Not fun, often fatal.
sloppy handling, with "swooping" motions, means something is loose,
either steering components or suspension components. You need to
check, on that car, steering linkage (including idler arm busings),
front brake support rods (otherwise known as track rods) -- the body
side bushings are usually shot by now -- front sway bar at the upper
control arm (often broken, hard to see with the wheels on), wheel
bearings, and ball joints. Loose suspension components make it "swoop".
Check shocks, too -- bad shocks make it roll faster (not further).
Missing rear swaybar links, also quite common, make it roll a huge
amount, this may in fact be part of your problem. They were gone on my
220D when I got in in 1996, close to the same age. Drove really weird
until I got them replaced. Cheap, too -- $18 each.
Also, jack the rear wheels up and check for play in the rear wheel
bearings and rear control arm bushings. If the wheel moves back and
forth easily, the bushings are out and it's really swoopy -- torque
steer in both directions. I know, they went on the 220D.
A Benz that old, especially if not maintained properly before you got
it, ain't gonna be cheap. Not low maintenance cars, really -- they can
be pretty good for a long time, but do require quite a bit or work
around 25 years or 250,000 miles.. hehe -- nothing else seems to last
that long!
Peter