Does the transfer case move at all while driving?

[freedom_in_4low]

Yes and then had it balanced to 10K RPM just to be sure since I had installed new u joints

Who said they balanced it to 10K rpm? As far as I'm aware the balancing machines used by most driveshaft shops tops out at 3300.

@Shawn at Tom Wood's ?

But if you drove without it and the vibration persisted, then that's good enough to know it's not the front shaft.

 

[macleanflood]

I'm having similar issues...4" lift...SYE...stock skid plate...not a huge vibration but noticible past 55. Pulled the front driveshaft...same issue...have messed with pinion angle adjusting rear lower control arms.

Noticed shiney spots on the gas tank...so I ordered RockJock aka Curry adjustable track bars and angled rear bracket. Should be here eventually...

-Mac

 

[Alatex]

Who said they balanced it to 10K rpm? As far as I'm aware the balancing machines used by most driveshaft shops tops out at 3300.

@Shawn at Tom Wood's ?

But if you drove without it and the vibration persisted, then that's good enough to know it's not the front shaft.

A local shop has a harmonic balancer and does custom shafts.

 

[Shawn at Tom Wood's]

Who said they balanced it to 10K rpm? As far as I'm aware the balancing machines used by most driveshaft shops tops out at 3300.

@Shawn at Tom Wood's ?

But if you drove without it and the vibration persisted, then that's good enough to know it's not the front shaft.

10K rpm is hard to believe, that is 3 times faster than our balancer https://www.superiordriveline.com/shaftsmaster/ will spin. It is also equivalent to the speeds at which a drive shaft would spin at around 250 MPH, generally speaking, depending on tire diameter and gear ratio. I wouldn't stand in the same room as a shaft spinning that fast. At any rate, if the vibration was there with the front shaft removed it is not the front shaft. So what else could it be? There is a guide to diagnosing some of the other possibilities here https://4xshaft.com/blogs/faq/diagnosing-drive-shaft-vibrations?_pos=1&_sid=d6ec76a03&_ss=r. One of those possibilities is that we didn't balance the shaft well enough. If all the other things on the list seem to check out give us a call and we can arrange to get the shaft back for a re-balance. It's not a common thing but definitely don't beat your head against a wall with a bunch of other things if it seems like it might just be the shaft. @Alatex

 

[Gollywomper]

10K rpm is hard to believe, that is 3 times faster than our balancer https://www.superiordriveline.com/shaftsmaster/ will spin. It is also equivalent to the speeds at which a drive shaft would spin at around 250 MPH, generally speaking, depending on tire diameter and gear ratio. I wouldn't stand in the same room as a shaft spinning that fast. At any rate, if the vibration was there with the front shaft removed it is not the front shaft. So what else could it be? There is a guide to diagnosing some of the other possibilities here https://4xshaft.com/blogs/faq/diagnosing-drive-shaft-vibrations?_pos=1&_sid=d6ec76a03&_ss=r. One of those possibilities is that we didn't balance the shaft well enough. If all the other things on the list seem to check out give us a call and we can arrange to get the shaft back for a re-balance. It's not a common thing but definitely don't beat your head against a wall with a bunch of other things if it seems like it might just be the shaft. @Alatex

One would think at those rpm’s out shafts would vibrate like crazy and flex.

 

[Shawn at Tom Wood's]

One would think at those rpm’s out shafts would vibrate like crazy and flex.

Totally, it is a little more than twice the "critical speed" of the shaft. Especially on a stock shaft 10K rpm is like tear itself apart and blow up fast. Like space shuttle re-entering the atmosphere fast. They might have meant 10K rpm as in the equivalent of 10K engine RPM or something. A lot of times people will say they balance a shaft to 100 mph or something like that, which is not exactly accurate but I guess they are trying to put it into terms they think the customer will understand. Or maybe they are just making stuff up. I don't know.

But again, that part of the story is not as important as the part where the vibration is still there with the front shaft removed.

 

[JMT]

Yes and then had it balanced to 10K RPM just to be sure since I had installed new u joints

Listen to this video, especially at 7:12 and following.

https://wranglertjforum.com/threads/how-to-properly-set-your-pinion-angle.228/post-1117120
EDIT: oh, I see now that @Shawn at Tom Wood's has chimed in. It’s his video. I think you’ll get your solution.

Also, I can’t remember if you said the shaft was new or been rebuilt, but don’t discount a bad ujoint or centering ball.

 

[Alatex]

10K rpm is hard to believe, that is 3 times faster than our balancer https://www.superiordriveline.com/shaftsmaster/ will spin. It is also equivalent to the speeds at which a drive shaft would spin at around 250 MPH, generally speaking, depending on tire diameter and gear ratio. I wouldn't stand in the same room as a shaft spinning that fast. At any rate, if the vibration was there with the front shaft removed it is not the front shaft. So what else could it be? There is a guide to diagnosing some of the other possibilities here https://4xshaft.com/blogs/faq/diagnosing-drive-shaft-vibrations?_pos=1&_sid=d6ec76a03&_ss=r. One of those possibilities is that we didn't balance the shaft well enough. If all the other things on the list seem to check out give us a call and we can arrange to get the shaft back for a re-balance. It's not a common thing but definitely don't beat your head against a wall with a bunch of other things if it seems like it might just be the shaft. @Alatex

It’s very possible that I’m an idiot and misunderstood the man that balanced the shaft