Quote:
Originally Posted by wilkin250r
But wouldn't a driveshaft imbalance, whether it be off-balance itself or yokes out of phase, be a CONSTANT vibration? It might be more pronounced at a certain speed, it might hit a resonant frequency, but it would be constant?
My vibration comes and goes. It's there, and half second later it disappears, and reappears a half second after that. It's there, it's gone, it's there, it's gone. Like I said in my earlier posts, it's got a rhythm to it. A cycle.
So I put it up on jackstands and pulled the wheels off, and revved it up to 55mph on the jackstands. Same vibration, but it had a different "rhythm" to it. Instead of a bruup bruup bruup, it was a constant bruuuuuuuuuuuuuuuup.
<<By taking the wheels off the ground, did you not end up with a "constant vibration?">>
Logic dictates that if my vibration comes and goes, it is changing. Even if it's a rhythmic change, has to be components that are changing with respect to each other. At any given speed, the driveshaft is a constant rotation, exact same speed. How can I get vibration that is changing from a rotation that is constant?
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/start rant/ You are entering and exiting a phasing in relation to the wheels while they rotate. Rolling resistance forces loading back into the driveline, which in turn can cause it to flex and rotate in an eccentric. One worn u-joint at the tailshaft could do exactly what you are describing. Especially given that you just replaced the carrier. Why exactly was that done? Flopping around, and making noise?
Logic dictates that when you are exasperated with a problem to the extent that you post the issue in a forum full of expertise, that you take whatever advice is offered, get under your truck with a flow chart and eliminate the many possibilities that have been offered, and not torpedo it or them. Dialogue with you seems to be along the line of when Na'aman the Syrian came to Israel in the hopes of receiving a cure for his leprosy, and instead he found lots of reasons to second-guess the directions of Elisha to simply wash in the Jordan. 2 Kings 5:10:14 Let me ask you, why ask for advice?
Maybe you are from the school that teaches that free advice is worth-less, compared to going to a shop and PAYING for it.
Maybe when you figure out what the problem turns out to be, you will post your findings back in here, Don Quixote. /end rant/