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Old 01-30-2019, 04:01 AM   #15
kazoocruiser
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Join Date: Aug 2018
Location: Bronx, NY
Posts: 215
Re: Chasing vibration

Wilkin250r, why are you dredging up an issue you had when you posted your comment and all of the discussions you are having here, were already addressed there?

http://67-72chevytrucks.com/vboard/s...85#post8108885

Flow charts, GM Service Manual - Driveline Vib Diagnosis

Thread started on 4-29-2012. You posted on 12-19-2017. To Quote:

Quote:
Originally Posted by wilkin250r View Post
I definitely have a "boom/beat" problem in a 72 I'm fixing up. The vibration is fairly high frequency, so I'm assuming it's a driveline issue and not a tire issue, but the vibration also fades in and out with a regular rhythm.

Am I correct in assuming the transmission HAS to be part of the problem? Exactly like you said, Keith, amplitudes adding (in phase) or canceling (out of phase). With a driveline imbalance or u-joint, it would be a constant vibration. It wouldn't fade in and out because there is nothing to change. The planetary gears in the transmission are the only thing I can think that would allow two similar vibrations to fade in and out of phase with each other, so one of the vibrations HAS to be in the transmission. Yes?

(Actually, as I type this, I suppose the ring/pinion gears could also allow two vibrations to add/cancel each other)
For shame, for shame. Shame on you.

You should be reported to the board administrators.

Last edited by kazoocruiser; 01-30-2019 at 04:10 AM.
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