Has anyone familiar with a drive shaft being out-of-balance? What causes this and what are the remedies?

thx!

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Mark Herzig
1995 E300D 153K
1985 300D 142K (sold)
1979 450SL 122 miles (sold)
1992 500E 127K (sold)
1987 300SDL 132K (sold)
1986 300E 161K (sold)

Hi there,
There are a couple of things you might want to check before worrying about the balance. First, check the nylon bushings that center the driveshaft. These are located in the ends of the driveshaft, and are replaceable. They center the driveshaft, and if they are worn, will cause the shaft to be out of balance. Sometimes they will cause severe vibration starting off from a stop, but then as the speed increases, the vibration goes away. Secondly, check the center bearing and U-joint for wear. The U-joint in the center will also cause the driveshaft to go out of balance if worn. The driveshaft is very closely balanced at the factory, so almost all problems are due to wear or damage. Good luck!
Richard Wooldridge

Check flex discs or center support bearing. Drive shaft does not go "out of balance" per se..It will create vibration if it isn't running true. The only way it can go out of balance is actual physical damage.

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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

Thanks guys for the input. I'm trying to diagnose with the dealer what is causing vibrations and they feel the drive shaft is out-of-balance. I had a blowout and the rim I put on was bent causing the vibration. I don;t know where the dealer gets "driveshaft out of balance".


I appreciate the experienced analysis, guys!!

__________________
Mark Herzig
1995 E300D 153K
1985 300D 142K (sold)
1979 450SL 122 miles (sold)
1992 500E 127K (sold)
1987 300SDL 132K (sold)
1986 300E 161K (sold)

Clunk sounds like the transmission locking into park. MB drive shaft problems are rare, except for flex disc. I would make sure that the ROCK didn't bend or damage any related mountings.

I had the same problem on my 380se. It vibrated from a standstill and went away when I got up to speed. Diagnosis - worn center bearing. Cured the problem immediately.

When drive shafts are manufactured, they are not perfect, and like wheels, they are balanced with small weights. Unless removed from the car or disassembled in any way, (or bent by accident), they should not go out of balance.If the shaft is dismounted, make sure all pieces are marked in order to replace it in original alignment.
When I restored my '59 coupe, I had to have the shaft (including the the U-joints) balanced as a unit.
I would think your problem is as stated in the previous replies. Ed

My 1985 300CD (135K miles) has a rythmic vibration problem that I haven't been able to solve completely. I had the original shaft removed and balanced (and the universal joint rebuilt) but that didn't help. Since then I've had two other drive shaft shops tell me that they won't even try to balance or repair the mercedes shafts because they are too difficult. I can't imagine why that would be so but thats what they said. I've also had bearings repacked, replaced engine/tranmission mounts, center driveshaft bearing, differential mount, and had the wheels balanced/checked about three times. I'm not sure what to do next.

Anyone got any suggestions?

I had a simular problem and did the same parts change as you did.
It was slightly better after changing the motor/tranny mounts and was remedied when I changed the timing chain.
Mostly noticed cruising around 3K with no load.
Guess the worn chain was setting up a harmonic engine vib.

Thanks Arthur, I haven't heard that suggestion and will discuss it with my mechanic. I'm willing to do most anything but have the frustration of not really knowing what will work.

Nic