About ready to give up- Front DS vibes, 01 xj- Advice appreciated

[the_weirdo]

Columbus, you have been fighting that vibration for years. I would try a new front gear set just in case the the existing has worn funny. If that doesn't work - try 5 gallons of gas and a lighter.

 

[#S194]

Check and see if your axle shafts are straight and not out of round as well. There has to be something out of whack in the front that the driveshaft is transferring up to the chassis when it's in. If that's not the case, go with the gas and lighter idea!

 

[hamman]

Have you tried a different yoke on the diff, seen those get tweaked and cause shaft run out. Make sure it seats properly to pinion. Check shaft run out with a dial indicator especially near the slip yoke.

 

[MOBBiN]

I recently devolped a similar problem on my 01. Mine has the "bass" sound from 30-50mph in 4wd. I took it into the dealership and they said my front drive shaft needed to be rebuilt. I'll be following this thread.

 

[bobnoxious]

4.56's/33's/ 4.5"/LA's...just fixed mine (same exact vibe) by installing L/O hub kit.

Glad nobody bought it when I was trying to sell it for less than half price last year

Ours also got worse when the gears were installed...much faster spinning driveshaft(s)

 

[Kevin108]

You've build your Jeep beyond everything it was ever intended to do. Maybe some vibes are just the consequence of its capabilities. If you'd spent half as much on better speakers as you have trying to fix it, you'd be happy already. Ignore it and just drive it!

 

[srmitchell]

Thanks guys. I figure it's free to ask, so I'd try. Maybe one of these days I'll just get the front shaft rebalanced, but for now, I'll keep it around 60 on the freeway. Save fuel too.

 

[yossarian19]

When did you go to 4.56?
Did you have the same driveshaft when you changed gears?
It really seems like the driveshaft is the problem, either joints or balance or both, but it seems relevant to know whether anything else changed at the time the noise showed up.
I mean, if the noise was already there but got worse when you re geared and no other parts got changed, then I'd say yeah, get the shaft re balanced by a local shop and see what happens.
Also, and I know you don't want to hear it, but just swapping the T case with no change is no guarantee the t case is good. I think in this case it probably is, but more than once I've gotten brand new parts that were bad out of the box. With used parts, no guarantees that one is better than another.

 

[Boostwerks.com]

Even though you checked your pinion angle, you may want to have it checked by a shop, or by a different angle finder. A degree or two off can make a substantial amount of vibration in my experience. It's also fairly easy to be a degree or so out with the typical magnetic angle finders.

Another thing you can do to check for DS balance issues is to throw on two large hose clamps with the screw part roughly 180deg apart from one another. Take it for a test drive to get a baseline on the vibes, and then rotate just one of the clamps to try and "tune" out the vibe. If you can reduce the amount of vibes, you should have the shaft rebalanced.

 

[srmitchell]

The vibes started when I went to 4.56. It used to happen when I would drive 80 mph+, but since I regeared, the shafts spin faster- So the vibes start sooner.

Good advice guys.

 

[mako my day]

I have exact same issues. This is probably going to make me sell this XJ that took me 7 months to build, and have not been able to drive it to the desert or mountains.

Smooth nice driving XJ, then.........
Re geared to 4:56, Also added Grizzly Yukon front auto locker = vibes at 58mph.
Rebuilt and balanced drive shafts = no change
Rear pinion has 4 degree shim.(1 degree low)
Front pinion adjusted 2-3 up, 0, and 2 - 3 down. No change in vibrations.
Tires new and balanced
Remove front DS, and vibes go away, and can drive smooth at 65.
Swapped drive shafts, front to rear, no difference.
Veeeeery discouraging.

 

[kastein]

Why would you sell it because of a driveshaft vibration? :huh:

Just spend 5 minutes pulling the driveshaft after wheeling and 5 minutes putting it in before going wheeling. It's 8 bolts and only one size wrench required.

 

[mako my day]

I hate bandaids. I would rather pay 5-600 (which I have done) bucks to have it fixed, than have the need to remove the DS, drive 2-10 hours to the mountains or desert, re-install DS, Wheel for a day, remove shaft and drive home.

 

[EricsXJ]

Why would you sell it because of a driveshaft vibration? :huh:

Just spend 5 minutes pulling the driveshaft after wheeling and 5 minutes putting it in before going wheeling. It's 8 bolts and only one size wrench required.

Depending on what type of bellypan / skidplate they have under there that is easier said than done.

A friend of mine had vibes that he could not get rid of but his was a LP30. After all the troubleshooting we could do it came down to 2 options. Build a HP30 or hub kit. Since he already had a ton of money tied up with an ARB and gears, he opted for the hub kit and was very happy with the outcome. It sounds like bobnoxious went the same route.

I've had a hub kit on mine along with 4340 inners and while it was a lot of money, it really made driving it on the street a pleasure. No vibration no noise.

For Sean and mako my day, I certainly would not give up or sell the rig. I would get a hub kit any day before doing that. True they are expensive but you might be able to find one used (have another friend that did that too). Or Heck since I'm getting a new front axle I might even sell you mine

 

[kastein]

LP30 to HP30 he could have swapped the ARB over and only had to put new gears in it, but that's understandable.

The other option is to build that dana 34 setup dgrigorenko came up with. If you've got access to a basic 3 axis mill and a lathe it looks like it should take a competent machinist/welder a few hours to do after reading over his thread and getting the parts.

 

[yossarian19]

I'd probably go with the hub kit or the Dana 34 / whatever axle swap before selling the car, but it would drive me crazy having an unexplained tech challenge like that. I mean... WTF is causing the vibration and why?
Could it be the gear setup / pinion and only transmitting to the vehicle through the driveshaft? it doesnt make much sense, since the trans / t case are mounted on rubber same as the control arms, but it's all I can come up with that hasn't already been covered.

 

[IH392]

Does the long arm have its own cross member? Maybe it's positioning the transmission/transfer case too low, causing bad angles for the front drive shaft. Is it possible to make some plates and raise the transmission so it sits very close to the trans tunnel?

 

[bobnoxious]

Yup...5x5.5 L/O hub kit from a previous build. I tried to sell it, but I'm glad everybody was too cheap to buy it for $5-600, as it has eliminated 2/3 of our highway vibes, and made our XJ pleasurable again. Front shafts do not want to spin that fast and remain vibe-free...the angles (especially lifted) are all wrong.

There is still a vibe from the rear that will never go away (every Jeep I have ever built has had at least some vibe, and I've built a lot, in every conceivable combo), but it's tolerable now...really wish I had 3.90 or 4.10 ratio to clear up the last bit, but it is what it is.

 

[330LICIOUS]

I just skimmed through the posts so sorry if this was mentioned already... have you checked if the front diff and transfer case yokes are not lashing in and out? they are allowed to have movement in terms of a couple millimeters turning (left/right), but should NOT have any loose movement in/out. I had vibes and this was the problem for me. good luck.

 

[330LICIOUS]

Why would you sell it because of a driveshaft vibration? :huh:

Just spend 5 minutes pulling the driveshaft after wheeling and 5 minutes putting it in before going wheeling. It's 8 bolts and only one size wrench required.

I was doing exactly this!! ... until I found out what my problem was (see my previous post above)