It could also be the driveshaft carrier bearing. But I would start off by changing out the diff fluid with synthetic or use staight 90w or higher to see if it will go away. If not then you need find a way to get down there and hear where the noise is located.


It might go away but be sure to properly support the vehicle if you're going to attempt it.

__________________
1983 123.133 California
- GreaseCar Veg System

I am interested in this as well and have posted previously on the subject. My 85 300SD continues to make a loud noise that seems to be coming from the passenger side rear. Have changed the diff oil too. I have had the vehicle on jackstands and running and cannot duplicate the noise. The noise is present regardless of pressing on the pedal or coasting. I also seem to have some driveline noise around the center of the car but thats a different subject. Also something of note, when the car was on jackstands, speedo aproaching 30mph, the rpms and speed increase dramatically. Is that the turbo kicking in?

__________________
1985 Mercedes Benz 300SD, TMU
2015 Chrysler 200S

This seems like a very common problem with these cars. I've had the same problem with whine since I bought mine. I've changed to synthetic gear lube and I've checked the wheel bearings, etc. It seems to be coming from the diff and maybe since the subframe mounts are old, the noise is being transmitted more effectively to the cabin.

I still need to have a look-see at the ring and pinion gears one of these days to see how much wear is on them and check the preload on the bearings.

Has anyone priced a new ring gear and pinion gear (that is, if they're still available) from the dealer parts department?

Curt

__________________
NoSnooz
Grand Rapids MI

84 190D 2.2 Auto 228,000

I've got Lucas synthetic in mine now. I am thinking about putting Swepco 201 in it which is what I use in my 911 race car. Could it be coming from the carrier bearing?

Usually differentials start whining when they wear out, due to an increase in the gap between the drive pinion and the gear. How about putting a custom made adjustment shim between the satellite carrier and the gear to move the gear closer to the drive pinion?

This should reduce/stop the whine and also minimize the "clunk" you feel when you are accelerating and suddenly release the accelerator. The same thing when you park the car and it rolls a bit before reaching the transmission park mechanism.

Any thoughts?

__________________
1982 W123 300D NA Euro, 300K Miles, 4-speed manual, 3.46 rear diff, early W126 front brakes, Penta rims with 205/60R15 FH900's, custom fitted (by me) audio system, more to come into the money pit... Soon to be installed: Bilstein HD, R107 front discs and 4-piston calipers, HD Suspension springs, wagon front swaybar.

I suppose if the ring and pinion gears don't have too much wear, one could shim it up behind the pinion (I wonder if those crush sleeves are still available... I think I'll need one plus a couple side bearings and seals too).

I'm hoping to get the bathroom tile project done so I can start farting around with the car again.

On another note, I managed to get some time tonight to make a steering gearbox adjustment and it seemed to tighten things up.

__________________
NoSnooz
Grand Rapids MI

84 190D 2.2 Auto 228,000

Not to hijack the thread...

The whine he refers to could be the bearings wearing out not the gears... It takes a lot to do damage to the gears, you really have to try destroy the diff gears along with the tranny.

to make sure its the differential i would get yourself a stethoscope(locally at autozone) and run the car on a lift. Use the stethoscope and make sure it is not the wheel bearings. Bad wheel bearings can be easily mistaken for a bad differential bearings when in fact it is the wheel bearings.
Good diagnosis will save you a lot of headaches...

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

But wheel bearings rumble, not whine, right? Don't wheel bearings make noise when taking a corner while driving? If so, it should be a bit easier to diagnose.

If bad bearings could make a whining sound, then it possibly could be the diff side bearings also.

__________________
NoSnooz
Grand Rapids MI

84 190D 2.2 Auto 228,000

no....

bad wheel bearings make a whining noise and increase in pitch the faster you go.

CV joints make noise when you take turns not wheel bearings.

So yeah differential side bearings could be shot.

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

is there away to repair a differential if it is noisy? Whatare the possible parts to be replaced? How long will it last in case of repair?

Well hindsight is 20/20. I had the low whine that was going away when load was taken off the driveshaft. Had been doing that for 3 or 4 months. hardly noticeable.

The car would also creep a bit on putting it in park.

In VERY short order (10 miles on the highway) it got louder, and let go.

Driveshaft was spinning, car wasn't moving. Towed to the shop..

I have a 85 300SD. Mercedes doesn't have whole rear diffs. They also didn't have much available for rebuild parts.

I have a used one on the way from stockton CA.

JP

__________________
________
1985 300SD
2001 Toyota Tundra - soon to be replaced with diesel truck
2006 Honda CRV

You're married, right?

__________________

Gone to the dark side

- Jeff

Hi all,

On the way to work this morning my 300D started making a whine I hadn't heard before. It persists whether the driveshaft is loaded or not, even in neutral. I felt all the wheels when I stopped and none feel any warmer than the rest. Doesn't really make that harmonic "rub-rub-rub" noise that I've heard wheel bearings make before. More like a constant tone. Pitching the car left or right doesn't seem to affect it either. I'm leaning toward the driveshaft carrier bearing. I have a 75 mile drive to get home tonight. I hope it holds.

Jerry

__________________
--
'85 300D - 195k

Sorry, I didn't really ask a question there, did I? I was hoping someone could help confirm the behavior of a bad driveshaft bearing. Has anyone experienced one and could describe what it sounded like?

It makes a sort of a 'woooooooooo' sound, anytime the car is rolling, under load or not. Pitch does vary with speed.

Thanks.

__________________
--
'85 300D - 195k

This is the same symptom my car has. Has anyone replaced the rear wheel bearings on a 124 wagon or sedan? It is a wagon only part according to some suppliers. Here is what Fastlane shows.

Well I found the DIY for the rear wheel bearings on the 124. I"m not sure it is my DIY ability.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss