From the searches I've found, I see people mentioning a flex-disc or something along those lines. I notice the thumping at low speeds 0-10 when
I step on the gas (lightly). It sounds like it's coming from the rear end. So,
my 2000 is just about at the warranty end. Is this a dealer visit or just the
way these cars act?

 

hi turbo, i would take it to the dealer if it were mine and still under a waranty, if not, jack the rear end of the car up, put some jackstands under it, and get under there and feel the driveshaft. if you can make it move up and down or side to side, see where the slop is. if there is none it may be in the rear end itself, the cv joints that connect to the rear wheels would be my next guess, but those usualy make a poping sound when they go bad. good luck.....

 

Yeah, I think you're right. I'm making an appointment in the morning. I live
kind of far from the dealer (40 miles) and that's why I try to do stuff myself
even if it cost me a few $$. But since I have a little over a month left of the
warranty, it makes sense in trying to use it. I'll also see if I can find more
info on the flex-disc I've read about. Thanks.

 

I feel a small vibration when my car first shifts into second gear. It is more pronounced when I have people in the back. What can this be?
Your Mercedes is equipped with a two-piece drive shaft. Between the two shafts there is a universal joint. Because of the length of the drive shaft, the u-joint was installed there to prevent any large angles at the front and rear, where it connects to the output flange of the transmission, and the input flange of the differential. Without getting to technical, it is a good thing to have this type of drive shaft cause it keeps objectionable vibration to a minimum. The u-joint is the one component that is mostly overlooked. A worn universal joint can cause vibration.
The bad news is that the universal joint is permanently installed in your original drive shaft and was not intended to be serviced by the do it yourselfer. Also it is very difficult to find the proper universal joint since it is not sold separately anymore.
Mercedes Flex Disc
The good news is many cities have drive shaft repair shops that can rebuild yours. They replace the u-joint, and rebalance the shaft, for a fraction of the cost of a new one. Usually this service runs around $150.00. If you live in a rural area, and don't have any service like this, check the classifieds in "The Star" magazine. It is publication geared to Mercedes Benz owners. The other option is you may purchase fully rebuilt units but at a much higher price.
Also inspect the flex disks. These can cause vibrations also. They connect your drive shaft to the back of the transmission and the front of the differential. They are large rubber disks. Look for any splitting, or reinforcement fibers sticking out. If you find any of these conditions replace them right away. The front ones should last about 75K miles and the backs to last at least 150K miles. First symptom is clunking sound while coasting to a stop.

Be sure to check the center bearing supports as well. These can wear out causing droning vibrations at cruising speeds.

 

i know what you mean about long drives to the dealership. i live in the ozarks and i am about an hour and a half away from one. it sounds like youre on the right track, i like to fix things myself when i can too, but i would personaly take full advantage of the warranty. it wasn't free, and you may as well get your nickels worth. good luck with the car, happy thanksgiving.

 

hey turbo i have that same problem , just sumtimes it will happen and i see you recently lowered your MB and i put new vogtland spring on mine.. same exact sound lol, this is what i did...

heard it in the back.. and i went and gently pushed down on the back on the car abovee the right and left wheels and the left one had a friction sound, e.i the sound we were hearing.. and it is a rubber disc or a "flex joint"

 

I'm still waiting for the dealer to squeeze me in. If all else fails, I'll pick up the
part and install myself. I just don't have the time right now and I think I can
get by without something falling apart.

 

I get a noticeable lurch the first time I drive off when the car was cold (over night) and it happens only in 2nd gear, then it will not happen again until the next morning. Anything to worry about?

 

I haven't heard of that before...... Sounds odd. Maybe someone has an idea.

I wonder if the tb linkage needs looking at or sensor on tb. I recall having an
issue on my 93 Saab in cold weather (it uses the coolant to keep the tb warm
- nice on cold cold days but sucked in the summer - so we added a coolant
bypass switch for summer use). A little off topic....