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300dt
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Discussion Starter · #1 ·
I bought a 83 sedan in june. I've had a vibration that seems like its coming from the mid to rear on the car. Its starts at about 45 to 65. At around 70 it seems to smooth out. It feels like it oscillating. At the higher end (65) the shifter vibrates at a very high frequency. I've had the transmission rebuilt and one of the axles replaced for torn boots. The universal joint replaced. flex disks look good. Was thinking maybe rear end. At the end of my rope. Any ideas out there?
 

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2x300D-83
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Hi!

Have you checked the swing damper that´s mounted with the drive shaft flange to the gearbox. Between the center and the "flywheel" there´s rubber that can get old and cracked. Maybe it´s on its way to get loose. You don´t want to drive 65mph when it completely comes loose, I can ensure you! It happened to me at real slow speed and the loose flywheel ring was knocking at the floor. When I changed the swing damper I probably got another one made for a gas engine. I can get some small oscillating when heavily loaded. You probably have seen how it´s mounted when you have taken down the transmission. Just a suggestion, but worth checking

Regards Anders
 

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Drive shaft carrier bearings and pinion gears (in the rear end) can also cause these symptoms. The cheapest, easiest to repair, and most likely culprit would be the carrier bearing, this is also known as a center bearing in the Haynes repair manual.
 

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1990 300SE, 1983 300D
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My car does it too. Luckly my dad has a repair shop so he can fix it no charge. I just to busy to get it fixed.
 

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bio-diesel!
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My 300d is vibration badly too...After many long trips, it's gotten almost unbearable...Rolling at very slow speeds produces a slow , bouncy vibration, and up to about 60mph it vibrates terribly...Then between 60-70, smooth .....Why and how much to fix[?]
 

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'81 300TD Turbo
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My '81 300TD Turbo does this too, but not that badly. It seemed to get better after changing the intermediate (center driveshaft) bearing, mount and transmission mount, but it still isn't totally gone.

I start getting some vibration at around 75mph and then it smooths out at around 80 and nothing really noticable beyond this.

Any rotating part will have some vibration, and they all have a resonant range where the vibration 'feeds' itself and it becomes beyond what would be normal, and in some cases beyond normal enough that they start to self-destruct. I don't know what that range would be for any given part and I don't know if anyone ever really cared to figured it out. But, I'm sure that whatever it is you would never be in the range if everything was within spec. Things out of balance could obviously change where this range begins and ends.

I would think gear related things would whine more than anything else, unless something was coming loose. Driveshafts, especially the rear half, could easily be the culprit if out of balance. I know the balance weights tend to rust and get thinner as time goes on, so it wouldn't be too far fetched to think this could be a contributing factor.
 

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Discussion Starter · #7 ·
Hey, thanks for all your input. Its been difficult finding time to reply. Turbosing, your problem is a bit more obvious, most likely one of your axles is shot. The center bearing as been replaced so i'm thinking the rear drive shaft or rear end. I'm not sure where the carrier bearing is. Maybe i should go with that first. again, thanks for all your help.
 

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hoppinjon - 2/10/2005 11:16 AM

I'm not sure where the carrier bearing is. Maybe i should go with that first. again, thanks for all your help.
If the center bearing in the drive shaft is what you're talking about, that is the same thing as the carrier bearing. A carrier/center bearing carries a drive shaft to reduce vibration or allow for high torque or horsepower engines. They, in essence, shorten the loaded length of the drive shaft.
 

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Actually the rear end is a box with two main items in it, one is the pinion gear and the other larger gear is known as the carrier gear and there is a bearing on each side of the gear in the housing. I would check the wheel bearings first because the rear ends seldom give any problems as long as there is lube in them.
 
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