What happens when you ignore that "little" driveline vibration! - Page 2 - PeachParts Mercedes-Benz Forum

Stevo · #16 12-08-2007, 11:46 AM

Quote:

Originally Posted by R Leo

Wanna place a bet on that?

The support bearing is pressed into place and basiacally just keeps the stub ends of the shafts aligned and isn't intended to contain the radial forces generated when a flex disk decides to take a hike.

The cut in that tunnel was made by the spider end of the stub shaft sawing it's way through like a skil saw.

Roger that. The U joint flailing around forward of the carrier bearing would soon come adrift causing a violent, catastrophic event

As in, never tow an MB very fast with the fwd section of the driveshaft out.

t walgamuth · #17 12-09-2007, 10:48 AM

I am not sure I am picturing what you are saying, but it looks to me as if the car could have been driven a long time with just part of the flex disc flailing. It also is possible that the car picked up a foreign object that got caught there and flailed about.

I agree it is tough to imagine the end of the ds coming loose with the spikot thing stuck in the back of the output shaft of the tranny.

I think if it were the spider doing the flailing it would be a bigger hole, too.

On my 190c fintail back in the seventies I once drove it til the flex joint had holes in the rubber donut around the bolt holes that nearly touched. It really didn't vibrate horribly but on take off and slowdown you could feel the slack being taken up.

Tom W

Mike D · #18 12-09-2007, 10:58 AM

Driving around with a piece of the flex joint flailing around sounds even worse than a sudden failure .

I don't think they drove it for long (notice the clean edges, no rust) but that bulge/dent was about an inch wide.

The key thing about it was the fact they just threw some new carpet over it and was on their merry way.

NewWilOrder · #19 10-16-2008, 01:28 PM

Thanks for the pics - kind of "drives" the point home...

Gurunutkins · #20 07-21-2009, 06:18 PM

Thought you might enjoy these non mercedes pictures here. sent to me by a friend. evidently the lady hit a mattress which whipped around the drive shaft and punctured the gas tank! it was the lack of gas that brought her to a stop after about 30 miles. It was towed to the dealer for a shimmy problem as well as not running

Tony H · #21 07-22-2009, 03:08 PM

That's amazing! I emailed the pic to some people in my office.
When I removed my driveshaft during my restoration work I found 2 of the 3 U-joints so stiff I could not move them. As you know they cannot be serviced and are staked in place. I had read horror stories on this and other forums of driveshaft disasters. I had my driveshaft rebuilt with serviceable u-joints with grease fittings-more peace of mind.

hookedon210s · #22 07-24-2009, 11:52 PM

On the vintage forum you would not have encountered what 80's and 90's air bag equipped cars do when the flex disc is neglected. The air bag sensor sits on top of the transmission tunnel waiting for a frontal impact or flex disc to fail. When the long ignored flex disc finally lets go the driveshaft smacks the transmission tunnel with such force that the driver side airbag is triggered. Nice surprise for the ignorant, unsuspecting driver. I own a 1987 560SEC which experienced such a failure with the PO. How the PO didn't know that there was as an impending failure I will never know. The transmission tunnel has a 3" wide gap where the failing flex disc repeatedly rubbed against it. Clearly took place over a not insubstantial length of time since the tunnel metal was stretched very thin. Unbelievable. Mark

anarchy · #23 12-13-2011, 10:22 AM

Thats NOTHING!!! I was driving down i80 doing about 80mph in my 87 300E and the flex disc broke which triggered the airbag to deploy in my face and knock my hands off the steering wheel

mercmad6.3 · #24 12-14-2011, 05:50 AM

Your air bag sensor is on the tunnel,no wonder it went off.
I did a diff for a customer recently who had swapped in Used diff...which ripped it's crown wheel apart.
The reason the diff was changed in the first place was because the owner heard a noise and his alleged ( former) mechanic told him the diff had gone.
It wasn't the diff making the noise but the flex disc,just like the first one in the thread.
It was in a 6.3 which eat discs anyway.
As he coasted down a hill on a city street,the flex disc came apart completely and took the rear of the gearbox out,plus the crossmember and the shifter rod
The drive shaft then hit the road and bent backwards taking out the center bearing.
The speedo cable was ripped out the housing.
He repaired it all himself .Luckily the finny uses the same rear housing etc on the tranny so it only cost a few dollars to replace things.
Then the diff went..

Palolo · #25 05-09-2012, 03:26 PM

Let me guess... S/He needs a new flex disc, but told you they think "it has a few more miles left in it..."

"uhmmm... Ok, let me email you a link."

pmally · #26 06-06-2012, 09:11 AM

My lesson was learned at 85MPH on i80 Sacramento CA it was a nice sunny day about 3 PM, I was driving along in my 87 300E when all of a sudden the #$&(^@# AIRBAGS DEPLOY IN MY FACE!! It took me about 5 seconds to comprehend what had just occurred I was extremely confused my hands, eyes, and head felt burned to make matters worse the car was filled with smoke I could not see anything. I was able to roll down the window grab the steering wheel and get to the side of the highway.

I was lucky! all the other drivers around me had seen what happened an were able to get out of the way had this happened in the hills where I live I would have most likely been in a bad car crash.

My question is
Dear,
Mercedes Benz Inc.
WHO THE HELL PUT THE AIRBAG SENSOR NEXT TO THE DRIVE LINE!
AND which other models have this defect must I fear death if my flex-disc fails?

I now own a 96 C220 I am still very afraid of these flex discs.

alabbasi · #27 06-06-2012, 02:53 PM

Quote:

Originally Posted by pmally

My question is
..... which other models have this defect must I fear death if my flex-disc fails?

Simlar thing happened in my 560SEL, thing thing to think about is the consequences if you're belting down the road and your drive shift hits the ground.

mercmad6.3 · #28 06-06-2012, 06:25 PM

OK, you get several weeks of advance notice when a flex disc ias on the way out. That judder under aceleration tells you something is wrong. You may not know what it is, but a visit to a garage is usually in order. If you take note of the little things that do not seem right,you avoid things like this.

rs899 · #29 06-06-2012, 08:22 PM

Yeah, most of us enlightened folks who drive our own cars would notice something. I could see my wife running into something like in post 20. Three days later she would say" I forgot to tell you there was this noise". I replaced all this stuff before I turned the 380SL over to her.

meltedpanda · #30 06-07-2012, 02:35 PM

I doubt this did not give warning , it had to have had a vibration or noise that would have been noticible