It is that time of year again... flex disc repair
 

Everybody get under your cars and visually inspect the driveshaft flex discs for signs of cracking or worse...
When they let go, your car will not be happy...
While under there, change your oil and transmission fluid, the brake fluid, and the differential fluid.
Inspect the boots on the axles as well.

Good advise.

X3, a failed flex disc probably could total $$$ an older car.

Also check the center driveshaft support bushing and bearing, that went bad on me while I was on the interstate last year. I didn't think about it, because it was hiding under that heat shield. Did not cause any damage but had to be towed.

Something in the driveshaft failed on my 1984 300D when my son drove it 600 mi away in San Diego. He said there was a vibration and whacking noise when driving. I asked him to peer underneath and see if perhaps a baby was flopping around on the driveshaft, but he didn't even look and took it to a shop.

I suspect they replaced a flex-disk but could have been the center bearing and/or support. Cost <$300. He was a medical student then so couldn't risk damaging his fingers. If a failed flex-disk, that was on me for missing preventative maintenance - fix it before it broke.

My 1960's Mopar cars have just a solid driveshaft, which works fine and their differential bounces up and down. Wonder why M-B decided a multi-part driveshaft with rubber disks and center bearing was required, especially with a short driveshaft and a body-mounted differential. Maybe just another German-thing like the over-complicated cabin-heating system w/ Aux Water Pump, Mono-valve (erratic), and giant 3-tube Heater Core (similar in BMW's).

Most likely choice was to remove engine vibration noise from the car.

Solid advice. I never checked the front part of the driveshaft on the 190D and it had a 1/4" gap with mix matched hardware and the guibo coming apart.. I was just driving this thing 80mph (!)

Another reason to park the girl for a bit..