Swaying on highway
 

Hi guys, I finally came back from being deployed and got a chance to drive my new (84) 300D. I noticed a funny thing on the interstate. When ever I speed up or slow down rapidly, ie, floor it or take my foot completely of off the pedal, the front end sways with the torque of the engine. It sways to the point that I have to compensate with the wheel. Is this normal???

not normal unless you were drinking :D Check your track rods...I'm pretty sure that's the symptom of their failure. Do a search on front suspension as I remember reading about it specifically when I was researching changing my LBJ's.

Also check for bad bushings on the rear control arms. When these are bad, you get terrific torque steer.

Rear subframe has to be dropped down to get the control arms off, by the way.

You can check by jacking the rear end up off the ground and see if the wheel moves forward or backward under pressure. If so, the bushings are gone.

Worst case you have rotted out rear control arms, but this is usually only on the W126 chassis.

Peter

The same thing happens on my '86 300E, but I know that it's the rear suspension arm bushings. Try this: when you jack up the rear wheel, put a long handled lug wrench on one of the bolts and lever it in both directions. If the bushings are worn, the whole wheel will move (a surprising amount, I might add), usually toward the front of the car, if remember correctly. On my car, at least, when the arms and bushings are replaced (they come as an assembly) the bolts have to be tightened with the arms in the same position that they are when on the ground under full weight, otherwise the bushings in the new arms will wear out prematurely. Yours may be different, I don't know, but I'm sure someone here does.

Don't forget to use the proper spring compressor if you do the job yourself.

Good luck with it.

W123 chassis has simple semitrailing arms, but you have to drop the subframe down to get the outer bolt out.

Diagnosis is the same, though.

Peter