Rear end noise.... - Page 2 - PeachParts Mercedes-Benz Forum

vwbuge · #16 10-17-2006, 11:28 PM

I really don't think it is a wheel issue. The driveshaft bearing got me thinking. I was on my way to work tonight and I was doing the ghetto lean on the armrest and I really felt it through there.

Maybe it is the bearing.

vwbuge · #17 10-18-2006, 07:46 AM

Well I'm home from work at 7am. I decided to throw on some old clothes and slide uner the Benz to have a first hand look.

It seems that my driveshaft bearing is shot. It is REALLY hard to see but I was able to grab the driveshaft and see alot of movement. I also noticed I could use a rear tranny mount. A few small cracks in the flexdiscs so I will probably replace them while I'm at it.

Wallknight · #18 10-18-2006, 10:44 AM

1st thing: shoot some penetrating oil on the flex disc bolts and let them soak a bit. Not only had my bolts seized up, but the shaft had actually seized to the disc metal pieces. The oil made quick work of it. And yes, do it all while you're down there.

vwbuge · #19 10-18-2006, 12:44 PM

How is it replacing that bearing? I found a pic online but I really couldn't get a good look under the car. Does it have to be pressed on?

Wallknight · #20 10-18-2006, 12:52 PM

i used this thread:
http://www.peachparts.com/shopforum/showthread.php?t=151923&highlight=center+bearing+thumping
go to the last reply

The actual bearing/support replacement is easy. getting the old bolts out is not. do get a new bearing, support, and flex discs, you'll be glad you did it all at once. Oh, and dont forget to have some circlip pliers on hand; you wont be able to do it without.

Surf-n-Turf · #21 10-18-2006, 07:35 PM

Quote:

Originally Posted by Wallknight

Thanks, Surf and Turf. After I posted, had another thought. the driveshaft is balanced, and on mine, seemed to have little weights attached in certain places. If one of them fell off, or if somehow something got stuck to the shaft, could that unbalance the shaft, causing it to shake, but again only at a specific speed? But then, why would the pitch increase?

Yes, the weights are balancers. If you lose one the shaft goes out of balance and vibrates at certain RPMs just like a tire would. Thus causing most failures of the center support. The pitch increase is coinciding with RPM increase on the shaft. Once it shifts gears, the RPMs drop. Therefore hitting the same RPM 3-4 different times during acceleration to highway speed. Just as an out of balance tire can wreak havok on your suspension, an out of balance shaft can eat up those flex disks, center support bearings, and U-joints.

Wallknight · #22 10-18-2006, 07:58 PM

maybe i misunderstand what he means by pitch. I have in my mind the sound of a wet belt squeeling, then increasing pitch as it dries then goes away. Frequency of the banging maybe what is meant.

diesel don · #23 10-19-2006, 09:41 AM

VWBuge:

I agree with an earlier poster that the bearing and rubber carrier is easier than the flex disc bolts. We just did this job and the need to 'press' the bearing on had me worried. Don't worry. It was a piece of cake.
However, you need to know how the flex disc sleeves have a 1/4 inch extension. In other words, after the bolts are out, you have to have a screwdriver up there to pry it apart.
The first time I did that job I mistakenly thought it would just fall once the bolts were out.

But overall the job is very managable.

Best of Luck

Diesel Don

vwbuge · #24 10-19-2006, 01:30 PM

I just ordered the parts today. Thanks for all the input. Hopefully I can get to it soon.

Wallknight · #25 10-19-2006, 07:56 PM

I put a little grease inside the rubber carrier, and the bearing slipped right in. I dont know if that's good long term, but it sure made the install easy!