1984 300D- Noise under the car

From what you have said, it sounds like it is time to have the brakes checked. Although Mercedes cars have the brake wear warning light on the dash, sometimes things go wrong and the warning light does not come on. The fact that the sound changes when you apply the brakes indicates that there may be something loose or the brake pads may be near the end of their uesful life.

The "swishing" sound, I am not quite sure about that, but the "clicking" from my experience could possibly be a bearing or bearings. Outers usually go first. Some questions to ask yourself. How many miles on the car and have the bearings ever been changed or repacked with grease? When were the brakes last done? You can pull the wheel and see what kind of thickness is left on the pads. And yes MB has a warning light on the dash to let you know when the pads need to be replaced providing that all components of that system are in place and functioning. The wires that insert into the pads and the metal contacts in the outer bearing dust covers were missing on my car.

Great, thanks for the input, I had front shocks replaced with Bilstens and also lemforder (dont know if this is how it is spelled) ball joints, noise is gone, but my brakes are not good anymore, have to push it all the way down to the floor. Well, the car has 292,000 miles on it.

My 1986 300SDL has a "shift kit" type of 1st to 2nd I mean like fishtail bark the tires watch your neck shift. All new shocks+ coils balljoints all rubber bushings brakes bearings carrierbearing propeller shafts every fluid and filter has been changed rubber rearend support and even put lucus trans shift stuff in there. Trans does drip alittle (B-2 piston?) I know most of these new parts do not effect the trans shifting but any and all info in diagnosing is good info. Trans and engine mounts are good and engine shocks are new as well.. Noah

When I bought my 300SDL the ABS wires were wore through and the light was no longer on so check. but the rotors were so worn you could see the turbo veins. If you still have noises the plastic "skid plate" can make all kind of noises if a bolt is loose or missing.

Hi Noel, you will need to post a new question under the correct category or the question or jerky shifts just won't get been seen by people looking for transmission problems. When you get it up I will try to answer. I have a new kit coming out that will help with this problem.