Author Topic: Troubleshooting high speed vibration  (Read 900 times)

revilla

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Re: Troubleshooting high speed vibration
« Reply #30 on: 03 October 2020, 04:35 AM »
Hi Tim,

Thanks for sharing your experience(s). Valuable.  What’s interesting, however, is that he didn’t have this strong vibration before. It started suddenly, presumably after changing the flex discs (?). Reason why I believe the “problem” is related to that. Either a shaft re-mounted at a different configuration in relation to the original (factory balanced) or the transmission support bracket tightened before letting the car sit on its own weight.  “Cheap” non original flex discs are won’t cause such a severe vibration in my own experience. Out of balance shaft and/or trans mounting bracket will in my opinion though.
Best to wait for Rolo to confirm or rule that out.
Robert
Robert
W116 1977 280SEL & 1979 280SE

Rolo

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Re: Troubleshooting high speed vibration
« Reply #31 on: 07 October 2020, 01:30 PM »
I need to chime in there.  Changing the flex discs did not result in the vibration.  To tell you the truth, we've had the driveline apart so many times for so many things, I can't remember when it started.  I notice now because everything is rebuilt and we cruise at Autobahn speeds.  Used to burn so much oil it was no fun to drive hard.  13,000 miles on the rebuild now and a lot of high speeds.

As a side note, a member sent me a private message.  Shop did as the message suggested.  It might be better now, but hard to tell. 

Jed

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Re: Troubleshooting high speed vibration
« Reply #32 on: 07 October 2020, 07:52 PM »
"it might be better now"

so what did the private message suggest and the shop do that might have made it better....I personally would love to see this to resolution.
1979 Mercedes 6.9 #5206 - restored
1979 Mercedes 6.9 #6424 - ongoing restoration
1976 Mercedes 6.9 #484 - restoration?

revilla

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Re: Troubleshooting high speed vibration
« Reply #33 on: 07 October 2020, 09:49 PM »
It might be better now, but hard to tell.

Come on Rolo. You suggested the vibration wasn't there then suddenly it appeared at precisely 85 mph.  You also mentioned it was a strong vibration making the car not fun to drive. The improvement, if any, should also be a black-or-white type situation; not grey.

If there's a learning here that's what our W116 forum is all about, to help others.
Robert
W116 1977 280SEL & 1979 280SE

Rolo

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Re: Troubleshooting high speed vibration
« Reply #34 on: 08 October 2020, 06:46 PM »
Sorry to be vague, the flex disc change could be the source, but we also took out the transmission soon after.  And then I changed the tires - twice. And then we dropped everything out again for more engine work.  On the private message, I need to respect the sender's wishes.