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2006 W203 C280 Estate 187 000km
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Discussion Starter #1
Good day,

When I pull away or shift gears, and I do not operate the clutch extremely smooth all of the time, there is a very noticeable 'clunk' and jerk from the transmission.

Engine Mounts where replaced recently, as well as the Flex Plate, I think. The car was jacked up today, and I inspected these components, they all look in good condition.

Is this 'n fault or a quirk in this car?

Regards,

Erich
 

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money pits of various forms
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Good day,

When I pull away or shift gears, and I do not operate the clutch extremely smooth all of the time, there is a very noticeable 'clunk' and jerk from the transmission.

Engine Mounts where replaced recently, as well as the Flex Plate, I think. The car was jacked up today, and I inspected these components, they all look in good condition.

Is this 'n fault or a quirk in this car?

Regards,

Erich
Your vacuum system needs attention. Either leaking or bad elements (leaking in the elements).
 

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2006 W203 C280 Estate 187 000km
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Discussion Starter #3
Your vacuum system needs attention. Either leaking or bad elements (leaking in the elements).
Hi,

Ok, I'm a bit confused. What does vaccuum have to do with that?
Unless you are referring to a Auto Tranny? I have a manual.

Regards,

Erich
 

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money pits of various forms
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Oh doh! Clutch! missed that. Yes diff mount time.
 

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Depends on the week
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Not necessarily.

I have new diff mounts and I've occasionally gotten this weirdo clunk as well.



It's from the clutch engaging (or disengaging) at a weird point in the torque curve that something in the drive line clunks. Not really a big deal in my book.

But if you want to change out your diff mount bushes, this is a perfect excuse to do so. :)
 

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W-1-2-3 Go!
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Check the center carrier bearing. The torque applied the moment the clutch engages could make the center carrier bearing wobble around its rubber sleeve and if this sleeve is gone it could result in clunking.
 

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2006 W203 C280 Estate 187 000km
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Discussion Starter #9
Hi,

Thanks for all your input, I will have that checked out during the next service.

Where exactly is the Center Carrier Bearing?

Regards,

Erich
 

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Check the center carrier bearing. The torque applied the moment the clutch engages could make the center carrier bearing wobble around its rubber sleeve and if this sleeve is gone it could result in clunking.
Also there is always the flex disks as well. Drive shafts can clunk going from R to D or reverse. Clunking is not a good thing.
 

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99 SLK230 Kompressor, 5 Speed Manual
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This is likely the differential mounts. If the car has been lifted often with a floor jack under the rear center section it will take them out. It is very quick and easy to check them. The ones that will likely give this problem are two mounts about an inch or a little more in diameter at the bottom of differential carrier. The bolts through them run fore and aft.

With a floor jack GENTLY raise the center section while watching these mounts for significant movement. If they are shot, it will be obvious as you move the differential center section up.

If they are tight, then the other suggestions in this thread should be checked.

If it IS these mounts, they are tough to change. It takes a puller to get them out without destroying the sheet metal carrier. Don't get the bright idea that you can get them out with a hammer. You will certainly destroy the carrier.

Hope this helps.
 

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That is the first argument I have heard against using the diff. Any other suggestion on how to raise the rear?
 

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W-1-2-3 Go!
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Also there is always the flex disks as well. Drive shafts can clunk going from R to D or reverse. Clunking is not a good thing.
Must have read "flex disc" when the OP mentioned "flex plate" on first post. Yep, the discs and center carrier bearing could cause clunking when they're bad.
 

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99 SLK230 Kompressor, 5 Speed Manual
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Yes, on the 124 car, you should not raise it by the differential. I've raised enough 123 cars this way that I probably should have worn out a floor jack or two, but doing it to a 124 car will eventually take out the differential mounts. With an auto transmission car, you might come closer to getting by with it because they don't get banged around in normal operation as much as a stick shift car, but they still go out.

I know it's a PITA, but you need to raise each wheel individually by the lower control arm or the rear jack pad under the rocker panel. Once you've had to change the differential mounts on a 124 you will go to all lengths to keep from having to do it again. It takes either the special puller or fabrication of a puller if you have a metal lathe handy. Also using that puller is a reall work out and the pullers don't hold up very well to an impact wrench. You will be huffing and puffing before you get both mounts out and back in with the puller.

Also, if you ever replade the differential mounts PAY CLOSE ATTENTION TO THEIR ORIENTATION. They are a strange rubber shape and if you don't get them clocked correctly they won't do their job correctly and might even fail prematurely.

Hope this helps.
 

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Must have read "flex disc" when the OP mentioned "flex plate" on first post. Yep, the discs and center carrier bearing could cause clunking when they're bad.
Speaking of I noticed on the E400 that there is a hoop that loops around the DS in the rear by the diff and there is no such hoop on the 300D. I assume this is to catch the DS if the flex disk fails?

If you jack up the car with the pads where do you place the jack stands?
 

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Speaking of I noticed on the E400 that there is a hoop that loops around the DS in the rear by the diff and there is no such hoop on the 300D. I assume this is to catch the DS if the flex disk fails?

If you jack up the car with the pads where do you place the jack stands?
Our '89 190E also has this hoop. Check your 300D, maybe there were signs the hoop existed before and the PO might have removed it.
 

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99 SLK230 Kompressor, 5 Speed Manual
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If it's going on jack stands, raise it by the lower control arms and place the jack stand under the pad. Also, there is a beam that runs along underneath the side of the car just inboard of the rocker panels. You can throw two post lift pads under there anywhere and lift it with no problems whatsoever. Jack stands there would be a little more of a problem ther because of the concentrated load on the small jack stand area.
 
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