There are many threads about the vibrations at 40-45 mph but noone has posted any answers.

My tires were rotated front to back and it still vibrates like heck on what feels like the rear right wheel at 40-45 mph.

Bearing wheel tire are ok

Can the axle do this? or loose axle bolt?

Or is this a bushing problem?

What do i look for under there?

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1984 W123 300CDT

tires out of balance?

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

I moved all 4 tires around and it did not affect this vibration. And it makes no difference hot or cold either.

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1984 W123 300CDT

i've been told that my lower ball joints are shot and that is what causes my vibration at 40-45 mph. perhaps you have the same issue?

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1984 W123 300CD silver/blue *230k*
http://www.fuelly.com/sig-us/45166.png

I had a vibration of sorts in the rear @ ~48mph. Figured it was tires and put it off. Recently, after reading some threads here, I decided to look at my driveshaft flex discs. Rear disc is shot and showing threads. The 85 is now parked till I get the disc and I am driving the 83.

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Scott - K3PSO
----
1984 300D turbo ~203k miles
2008 FourWinds Hurricane 31' RV

Past
'85 300D turbo ~280k miles
'83 300D turbo ~300k miles
'05 Mini Cooper convertible
'96 BMW R1100-RT
'71 Honda CB175 - multi-winter project
'82 Honda CB450 NightHawk
'85 300D turbo ~328k miles
'75 BMW 2002
'66 Beetle

Im going to look under and try to diagnose this this week.
Ill keep you guys posted to what i find.

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1984 W123 300CDT

My vibration at 30-35 was the driveline carrier bearing holder.
My vibration at 40-45 was a right rear axle that was wearing out at the tire side joint.

Took a while to track down this vibration but now it is getting worse so it was easier to find.

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1984 W123 300CDT

Was the driveshaft carrier bearing making a noise?

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1983 240D 3.0T 4-speed manual, now sold

1989 Subaru GL Wagon 5-speed Touring Edition

My '83 has a slight vibration at that speed, most pronounced under load. Your instinct would point to the DS being out of balance, but this car has a rebuilt DS and new flex discs. What points to the axle is that if I put some weight in the car so the axles are absoultely straight, the vibration goes away.

The carrier bearing made no noise. It was ok but the rubber holder wore out after 6 months it was the one in the blue box. I bought the red box this time and no problems.

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1984 W123 300CDT

rear vibration: front/rear flex discs, center support bearing, subframe bushings, axles, bum pumpkin, tires, wheels not balanced, springs/shocks related--these are the common causes.

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