hi all, I've had this noise coming from the rear of my car for a little while, and I have reason to believe its in the differential because The sound is very similar to the sound my jeep made when the differential had a bent housing, its like a weird rotation noise, kind of like something is scraping when rotaing around.

My rear tires are new and have been balanced and checked out by my tire shop and have no problems, are not out of round, and the wheels are not bent. The reason I am pretty sure it isn't the tires is that it will make the noise if going 2 mph, and that would not be fast enough for the tires to be the cause of the noise. and since it has been checked by my tire guy, it doesn't seem likely that the tires are the culprit.

A german friend of mine, when he visited a little while ago, said he had a similar noise and it was the tires, but in my case the tires checked out ok.

The sound is like a Wuh-wuh-wuh noise.

I plan on getting it fixed at my mechanic, I was hoping someone would be able to give me a little heads up as to what it could be.

Is it one of the Rear drive axles, or could it be a missing tooth on a differential gear? Maybe its a bad bearing? Maybe a rear suspension component? Could it be a flex disc? My car's shifting has gotten a bit harsher lately, but the harsh shifting is intermittent. it shifts smooth sometimes, and harsh sometimes.

Could trans mounts or motor mounts cause this?

Could it be worn bushings in the rear suspension?

Rear links, or maybe the differential fluid is worn out or something.

I really can't describe the sound better than a wuh wuh wuh noise.

What could this be, and what could it potentially cost to fix if it is something like the differential...

When I take my car to my mechanic, I plan on having him do other work as well, like change all the fluids, and lube everything nicely, and replace any worn rubber on the car.

If it is the differential, do you guys recommend changing it out for a different gear ratio to make the car quicker off the line? I never plan on driving faster than 100 mph ever, so I wouldn't mind losing some top end speed.

Of course I really hope it is something simple and not too expensive to fix.

I just know the sound is annoying, so I now drive with the stereo a little louder than before so I don't have to hear it as much... hehe

ohh and the sound is there at any speed, and gets quicker as I go faster. I have no noticable vibration coming form the car at speed, but I do have slight vibration.

Thanks for the help everyone.

Alon

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'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

HEYthats the same noise i was getting from my 300ce and i had my flex disc replaced buti have not really tried to listen for the sound again. I useally here the noise if i take my car on a long trip but i havent done that lately but i will be going on a long trip next week and ill see if i still here it or not and if i do i will check more into getting it fixed!

I may have the same noise. I have posted under,

"Weird ghost noise coming from under car".

A wuh-wuh-wuh noise that already can be heard at 2mph does not sound like a differential noise to me. I think it can be found near or in one of the rear wheels (one wheel lug that is just s little too long has the same effect).
To determine where the sound is coming from, you can drive the car while somebody is listening for the noise in the trunk...(beware not to get into trouble with someone in the trunk).

greetingz,

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1990 300SL-24
1993 C250D with a minor 600+k kilometer
www.MBenzNL.com(the Netherlands)

hell of an idea there MB better yet could tie someone to one of those mechanics scooters and drag em under the car sorry i couldnt resist that one

Alon,
My wild guess is a bad bearing.
Now to test the diff.so you get a peace of mind,
run the car to 40 mph. Engage cruise control,
and shift to neutral.If its the diff.,youll hear
the same noise according to my mechanic.
Hope its help.

Clauser1

Yes thats why I thinks its the differential,

My jeep made same noise and its diff was bad.

Happens in neutral and at any speed, gets faster as I go faster.

So if I end up needing to replace it, what do you guys think of switching from the 3.07 in there now to lets say a better ratio for quicker acceleration at the loss of top speed.

I still have yet to take it into my mechanic. as I need to find time to do it.

The sound I have is not a whine noise or ghost noise, its more like a wobble type of noise, like something metal is uneven and grinding on one side when it rotates.

The only way I can describe it is it sounds like the noise is an out of round tire, but my tire shop has checked them several times and they are also new, and they balance out and all just fine. I do not have vibration when driving, just a noise that sounds like metal to metal contact almost, but not quite.

Alon

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'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

john,

I couldn't agree more, it might be too expensive, but my mechanic is so reasonable, that he might be able to do it for less, if so I will do the diff swap,otherwise, I'm just gonna have him fix it and at the same time, drop in the lowering springs I have.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon