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Drive train clunk

3K views 17 replies 6 participants last post by  bnZE430/1999 
#1 ·
Hello guys...

So here is my issue... I was driving down a parking lot with all the windows of my coupe lowered and NOT stepping on the gas pedal. I was maybe doing like 5 mph... anyway, when I would put my foot on the gas I would hear a clunk from under the car... took my foot off the gas then put it back on and again a clunk... I did this several times with the same clunk every time I put my foot on the gas... any suggestions? I didn't feel a thing only heard the sound. I looked at the flex disks and they have hair line cracks... but my engine mounts and trans mount are bad... other components look fine... the exhaust looks tight
 
#2 ·
If you know the engine and trans mounts are bad, that's the place to start.

Did you inspect your center carrier/bearing? That's another suspect.

Good luck.
 
#8 ·
any DYIs on this? I searched Carrier bushing w140 and didn't see anything.
I did this procedure on my car recently, but did not do a DYI write up on it. Perhaps I should...
 
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#9 ·
Its not a hard task with a car lift. mine is bad I started hearing the clunk/clicking sound last week and i have 148900miles recently I have driven my w140 as a daily car. Okay here is the instructions, You need to remove the exhaust and then the flex plates make sure to mark the driveshaft.

the bearing was tricky if I remember correctly. Another down side is the rubber center support is a hard plastic I bought one for $125 if I remember correctly.

Its also a perfect time to replace flex discs, driveshaft bushings and exhaust gasket also the transmission mount. I am only hoping mine lasts till December 20th. I know my flex discs are good I replaced them 3-4years ago.
 
#10 ·
Unlike when changing the flex disk where you don't need to drop the exhaust ...not the case with the center support bushing and bearing. Make sure you get the bushing from MB. Mark the drive shaft, remove the driveshaft, pull off other support bushing, use a puller to remove the bearing and the reverse to install. Don't forget the preload requirement for the bearing as specified by WIS. Of course change the flex disks at the same time. This should last you another 175K miles.

Shimshon
 
#12 ·
I believe center support bearing comes with the mount all together. Every time I've ever had clunking when accelerating its been flex disc mounts which ruthless stated, center support bearing. I've even had worn rear control arm bushings and that has also made clunking sound. Glad it found out where it was coming from. With lift should be pretty easy. Lets us know how it works out for ya! ?
 
#13 ·
You have to inspect the driveshaft there is no way we can really tell without being there. the driveshaft bushings are at the ends of the shaft. Once my computer resets (windows update is unstoppable on these damn windows 8) I will upload a diagram of the driveshaft and mention which numbers to check. will post it up in 30minutes
 
#14 ·
The end bushings are numbers 14 and 29 these vary on the year of the car and some other stuff I am not aware of but on mine it was about $300 together.

flex disc is number 89 these are roughly $175 a piece (should come with new bolts and nuts)

bearing is number 35 this part is roughly $40 at the dealer

center support rubber part is number 39 is about $175 at the dealer (checked my invoice to be sure on the price)

How to inspect them:

for flex discs look for cracks and make sure its not lose

bearing make sure it doesn't make noise

center support look for wear and cracks (most of the time they deteriorate)

end caps are like dampers and I dont really want to say this sentence online but they are sort of unnecessary when I had a differential rebuilt on a w210 they actually reused the worn out end cap bushings and said it makes no differences unless its completely ripped apart.
 

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