Mercedes-Benz Forum banner

1 - 3 of 3 Posts

·
Registered
81 300TDT WAGON , 82 300DT SEDAN, 84 300TDT WAGON(retired),
Joined
·
442 Posts
Discussion Starter #1
I replaced the two flex discs and center bearing / support.
Now the knocking is gone.
But I can feel the vibration when reach 100km(about 70miles), I marked the two pieces of drive shaft when I removed them and I checked the mark when I put them back.
Are they out of balance?
What can I do now? Take them off and re-install them? How to re-balance them?:bowdown:
 

·
Registered
Joined
·
507 Posts
Mine does the same thing. I think it's all in my head, though my shaft realignment is much more suspect than yours I imagine. I used the dot method described in the Peach Parts tutorial, which made me dubious about the shaft re-alignment.

You could remove the shaft again and take it to a driveshaft shop that could re-balance it. You would probably find this service at a shop that fabricates driveshafts for off-road vehicles, race cars, or other applications.

I think maybe what is happening is that the shaft was already out of balance from a previous job and that when the center bearing bushing is fixed, it constrains the driveshaft more than the busted rubber and thus passes the vibration into the unibody of the car. When the bushing was bad, it allowed more movement of the driveshaft without that movement being directly transferred to the body. Now that the rubber is tight, it passes every little vibration into the floor. Does that make sense?
 

·
Registered
81 300TDT WAGON , 82 300DT SEDAN, 84 300TDT WAGON(retired),
Joined
·
442 Posts
Discussion Starter #3
Mine does the same thing. I think it's all in my head, though my shaft realignment is much more suspect than yours I imagine. I used the dot method described in the Peach Parts tutorial, which made me dubious about the shaft re-alignment.

You could remove the shaft again and take it to a driveshaft shop that could re-balance it. You would probably find this service at a shop that fabricates driveshafts for off-road vehicles, race cars, or other applications.

I think maybe what is happening is that the shaft was already out of balance from a previous job and that when the center bearing bushing is fixed, it constrains the driveshaft more than the busted rubber and thus passes the vibration into the unibody of the car. When the bushing was bad, it allowed more movement of the driveshaft without that movement being directly transferred to the body. Now that the rubber is tight, it passes every little vibration into the floor. Does that make sense?


Totally agree with you.
I am not in the mood to remove them now. I will keep the speed under 70km, and try to replace them next summer.
 
1 - 3 of 3 Posts
Top