Y'all have me scared to do my re-gear

Just within the last few months I’ve heard of 3 people who had it happen after a re-gear.
@Chris Here on the forum? Is there a common issue that seems to be occuring here? I still have about 20 pages of Bob's pursuit of vibes to read, but if someone could give me the cliff notes that'd be appreciated. Did it ever get resolved?
 
No, they are a consequence of a cyclical harmonic created when both shafts turn. You can pull the rear shaft and drive only on the front one generally without the vibe.
Out of curiosity have you seen this issue on rigs with an atlas or is it limited to stock transfer cases?
 
@Chris Here on the forum? Is there a common issue that seems to be occuring here? I still have about 20 pages of Bob's pursuit of vibes to read, but if someone could give me the cliff notes that'd be appreciated. Did it ever get resolved?

Like Blaine said, it's about 1 out of 10 Jeeps. Maybe nothing to worry about, but I'd still budget for a manual hub conversion kit, because you simply never know.

It didn't happen to my first TJ when I re-geared, but it happened to my second TJ very badly after re-gearing.

No, @bobthetj03 never resolved it. There are some people like he and @psrivats who seem to have something far worse than what most people experience (which is resolved by a manual hub conversion).
 
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Out of curiosity have you seen this issue on rigs with an atlas or is it limited to stock transfer cases?
Although I have done several Atlas installs, they are still a very low statistical number so fairly irrelevant. In fact, I wouldn't state one way or the other because that will get totally blown out of proportion and turned into "ya'll fuckers are gonna need an Atlas, 2000 dollars worth of high Zoot driveshafts, and a hub kit if you regear." Yeah, ain't going there at all.
 
Thanks. So their are two cures? Spend time creating the absolute proper angle or manual hubs?
On a scant few, you can fine tune the angles and bring the top speed up a few miles per hour but it will generally be a lower than optimal number depending on the driver. Depending on the rig, that can consume many hours of time and piece by piece verification of parts to determine viability.
 
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Sounds like its a shot in the dark then. Plan and budget for a manual locking hub. If I end up not needing it, great!
That money goes to another part of the jeep. Thanks.
 
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Having been through the "re-gear to 5.38" vibes and eventually resolving them with a hub kit, and having read everything or almost everything ever posted on the subject on regearing and resulting vibrations, Blaine's observations are spot on:

I'd put the number at about 1 in 10. I'd also put the vocal intensity of the 1 at very high which tends to drown out the 9.

We've narrowed it down to spending the least amount of time possible to get them dialed in. . . . We do the known good methodology to dial it in and test drive it at the driver's requested common highest speed and it is pretty easy to tell if it is going to respond well or be a little bitch about it. At that point we stop, spend no more time on it and put further efforts into a hub kit. . . .

Most with the pre-03 are likely not going to be in the higher probability group. The problem generally happens with the Rubi case, 42RLE, and the lower gear ratios that spin the driveshafts faster.

Note the prodigious lack of definitive terms.
[Italics and bold supplied]

There is no reason to shy away from re-gearing if a different gear ratio is necessary to successfully run the tire size you need to run.
 
Sounds like its a shot in the dark then. Plan and budget for a manual locking hub. If I end up not needing it, great!
That money goes to another part of the jeep. Thanks.
Statistically, it isn't much of a shot in the dark overall. That 1 in 10 number is an educated guess based on observation and I am far more observant than most. If you asked me to nail it down further, I would factor in the earlier rigs with fewer issues and move that to 1 in a 500 or even lower.

If we start defining it further by risk, the highest risk group will be the 03-06 Rubi, long or short wheelbase, 35's and 5:13 or 5:38 gear sets with the auto trans.
 
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That's 1 in 10 of the TJ owners who frequent the Internet forums or Blaine's shop who happen to own an 03-06 with the 42RLE transmission and 241OR transfer case who has re-geared to 4.88, 5.15 or 5.38, not 1 in 10 of everyone in the TJ universe who has re-geared their '04 TJ from 3.73 to 5.13.

The sky is not falling.

Yet.
 
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One last question while this thread is decently active. Assuming that the vibratiuons happen after a re-gear, should I go straight for the maunal locking hubs? Or try to diagnose? Obviously I'd rather not throw money willy nilly at a problem if I can attempt to fix it, but I also understand my time is not worth chasing a what could be a pipe dream.

So by purchasing a hub kit, vibrations should disappear? Or will dissapear?
 
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That's 1 in 10 of the TJ owners who frequent the Internet forums or Blaine's shop who happen to own an 03-06 with the 42RLE transmission and 241OR transfer case who has re-geared to 4.88, 5.15 or 5.38, not 1 in 10 of everyone in the TJ universe who has re-geared their '04 TJ from 3.73 to 5.13.

The sky is not falling.

Yet.
That and anyone who takes that 1 in 10 number as gospel is a fool.
 
One last question while this thread is decently active. Assuming that the vibratiuons happen after a re-gear, should I go straight for the maunal locking hubs? Or try to diagnose? Obviously I'd rather not throw money willy nilly at a problem if I can attempt to fix it, but I also understand my time is not worth chasing a what could be a pipe dream.

So by purchasing a hub kit, vibrations should disappear? Or will dissapear?
Make no assumptions.
1-verify driveshafts are good, balanced perfectly, and in viable condition since they are now spinning faster.
2- verify that rear pinion angle can be dialed in by pulling the front driveshaft and doing the work and test drives.
3- Only after the rear is done should you install front and see what happens. Do the work with a mindful eye on steering and drivability. It does little good to dial out the vibes with a low caster angle and put up with shit steering.

Diagnose, hypothesize, test, use the results to create a forward path to resolution.
 
If we start defining it further by risk, the highest risk group will be the 03-06 Rubi, long or short wheelbase, 35's and 5:13 or 5:38 gear sets with the auto trans.

Well that really sucks because that's the exact group I'm in. lol

If I ever re-geared, 5.38s are what I would go with for 35s and I have an automatic transmission for my '06 Rubicon.