My 1983 Mercedes Benz 240D Diesel has a pretty nasty shudder/vibration that takes place during acceleration when the car reaches 20 mph and only at 20 mph. It does this regardless of which of its four gears I’m in. Just wondering if anyone had any ideas what it could be.
Thanks
I would have the suspension parts checked. If you have a good independent Benz mechanic they should be able to find it for you.
Well, at 20 MPH you are approaching the Vmax of that car. It’s going to shudder when running wide open like that :). I kid. You may want to check out the motor mounts. There’s also a slim chance that the driveshaft may be unbalanced.
thanks for the comments. I’ve heard that motor mounts and an unbalanced drive shaft are notorious for causing a shaking in the car during acceleration. However, what continues to puzzle me is why does it only shudders at 20 mph. When idling the car sounds normal. At highway speed the car sounds and feels normal. It’s only during acceleration when 20 mph is achieved that the vibration is noticeable.
Is the vibration in the steering wheel or the whole chassis?
You’ll need to get the car up on some good stands and get under it.
On stands the rear wheels can be slowly and carefuly rotated to help diagnose.
Check the flex disks at the front and rear of the drive shaft. The flex discs should look solid, not frayed. If the bolt holes are showing rusty dust then somethings loose.
Next check engine mounts,transmission mounts, the carrier bearing on the drive shaft and the rear diff rubber mounting. Next check the U-joints on the independent rear axles. They are under a rubber boot. If the boot gets torn or worn the U-joints fail quickly.
If the vibration is in the steering wheel areas to check would be the tires, the wheels. the sub frame mounts and of course the front suspension system.
Benzman