Hypothetical vibration question

[Ghoste]

If you had a driveshaft runout issue while you were breaking in a new ring and pinion, would that cause an uneven wear on the ring gear and lead to a surging vibration later on?

[RD]

i am not saying i will have the answer, but what exactly do you mean by a driveshaft "runout" issue?

[Mefirst]

Did he mean unbalanced drive shaft ??

[RD]

Did he mean unbalanced drive shaft ??

i am not sure Me.  I have never heard of a driveshaft runout issue.  got me befuddled.

[Mefirst]

Well if the driveshaft is unbalanced that would shorely cause vibration.. But I dont know how that would affect the ring gear, the driveshaft universal joints would probably take the most beating.. or ??

[RD]

an unbalanced driveshaft will also cause problems on the output shaft in the trans, especially the rear pushing and output shaft support.  The u-joints would most likely fly before then, but the vibration could cause a pinion bearing problem and then go to the ring gear.  But i have never heard of a bad ring gear pattern due to vibration.  just cuz i havent heard it, doesnt mean it doesnt happen.

[Ghoste]

Sorry.  I mean a bent driveshaft but balanced.

[ChargerRob]

How did you balance and bent driveshaft? 

[Mefirst]

Sorry.  I mean a bent driveshaft but balanced.

What Is that even possible

[RD]

wowsers....    i guess it matters on how bent the driveshaft is, but if it was balanced, would we be having this thread in the first place?  obviously the bent nature of the driveshaft is in question, and the fact that you have vibration tells me this, the driveshaft is not balanced.  I imagine your u joints, pinion bearing, ring gear, and trans output shaft are hating your driveshaft right now.

[Ghoste]

We're way overanalyzing it.  It is actually hypothetical.  I see "surging vibration" questions all the time on various forums and after a day with too little sleep, well, here we are.

So, a drivetrain vibration.  I don't care what.  Bent.  Unbalance driveshaft.  Broken trans mount.  Take your pick.
A new ring and pinion being broken in under these conditions.
Initial cause of vibration repaired.
New vibration-surging.
Could it be caused by a strange wear pattern on the ring gear?
But I think RD has answered the question already. 

[ChargerRob]

  Glad that's over with.

[Ghoste]

I'll try not to do it again.  I was kind of expecting an engineering answer about specific harmonic frequencies esatablishing sympathetic imbalance in the whatzits and the whoozits or some thing like that. 

[RD]

I'll try not to do it again.   I was kind of expecting an engineering answer about specific harmonic frequencies esatablishing sympathetic imbalance in the whatzits and the whoozits or some thing like that.  

vainglory didnt answer here or you would have seen that 

[Chryco Psycho]

with the load on the pinion brgs it would take huge pressure to cause the ring & pinion to wear unevenly , it could be possible but I highly doubt it would cause uneven wear , more likely the pinion was dropped & bent 

[Ghoste]

Well remember though, this one isn't for an actual problem.  It was just a goofy "what if" question.

[RD]

Well remember though, this one isn't for an actual problem.   It was just a goofy "what if" question.

well ghoste, stop it, you are making us hurt our brains 

[Ghoste]

   Awesome.  I'm one of the dumbest guys on here and I made you hurt your brain.  Ha ha.

[firefighter3931]

  Awesome.   I'm one of the dumbest guys on here and I made you hurt your brain.   Ha ha.

Hardly...quit sitting in the weeds you sandbagger     It's a perfectly good question and the answer is yes. Runout refers to an "out of round" driveshaft. There is a spec for "roundness" of the tubing that would be considered to be in the "acceptable" range. Anything that exceeds that spec has too much runout. Ideally you want to be able to balance the DS with as little weight as possible. A bent DS is a whole different issue alltogether.

Ron