Vibrations after lift install

Khoule

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Jan 24, 2019
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Michigan
After I lifted my Tj I got some driveline vibes. Installed an sye and cv driveshaft to fix it but I am still getting a vibration. Both my front and rear pinion angles match up with the driveshaft angles, replaced the u joints in the front driveshaft and axle shafts, so it seems the vibration is coming from somewhere else. It is not a constant vibration like it was with the driveshaft, it's more periodic. It'll vibrate for about 2 seconds, stop for about 2, vibrate for another 2 seconds, stop for 2 seconds and keeps doing that same pattern. Any suggestions?
 
Hope you sort it out and don't become part of of club you don't want to be a part of. Read these for clarification.

https://wranglertjforum.com/threads/harmonic-vibrations-in-jeeps-a-new-theory-please-read.15144/

https://wranglertjforum.com/threads/re-geared-now-i-have-a-vibration-above-50-mph.4235/

https://wranglertjforum.com/threads...ations-after-re-gear-to-4-88-or-deeper.12218/

There are more out there, and some not re-gear related. I've found threads of folks getting these harmonics after doing a SYE/DC drive shaft. Removing that harmonic balancer on the output of the transfer case may have something to do with it, but it's all speculation so far.
 
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After I lifted my Tj I got some driveline vibes. Installed an sye and cv driveshaft to fix it but I am still getting a vibration. Both my front and rear pinion angles match up with the driveshaft angles, replaced the u joints in the front driveshaft and axle shafts, so it seems the vibration is coming from somewhere else. It is not a constant vibration like it was with the driveshaft, it's more periodic. It'll vibrate for about 2 seconds, stop for about 2, vibrate for another 2 seconds, stop for 2 seconds and keeps doing that same pattern. Any suggestions?
Intermittent vibrations are often somethings too loose, too tight or somethings contacting something else that it is not supposed to.

Does the vibration change with speed or making a turn?
 
Hope you sort it out and don't become part of of club you don't want to be a part of. Read these for clarification.

https://wranglertjforum.com/threads/harmonic-vibrations-in-jeeps-a-new-theory-please-read.15144/

https://wranglertjforum.com/threads/re-geared-now-i-have-a-vibration-above-50-mph.4235/

https://wranglertjforum.com/threads...ations-after-re-gear-to-4-88-or-deeper.12218/

There are more out there, and some not re-gear related. I've found threads of folks getting these harmonics after doing a SYE/DC drive shaft. Removing that harmonic balancer on the output of the transfer case may have something to do with it, but it's all speculation so far.
I haven't re-geared yet, still on stock 3.73. I did notice by front pinion seal is leaking but I haven't had the time to get around to replacing it. Is it possible the yoke or bearings inside are bad causing the vibs? When I did my SYE I did have to remove the stock harmonic balancer. Anyway it would be related to that?
 
Intermittent vibrations are often somethings too loose, too tight or somethings contacting something else that it is not supposed to.

Does the vibration change with speed or making a turn?
The vibration starts around 55-60 mph and does not change in intensity as the speed increases. It can be felt in the pedals, the seat, the console and steering wheel.
 
I haven't re-geared yet, still on stock 3.73. I did notice by front pinion seal is leaking but I haven't had the time to get around to replacing it. Is it possible the yoke or bearings inside are bad causing the vibs? When I did my SYE I did have to remove the stock harmonic balancer. Anyway it would be related to that?

Yes, it could be related to that. Jeep put that balancer on there to dampen something. That is one of the pitfalls of doing an SYE that few of us think about. Sadly, you can't re-install that balancer after the SYE, so it is a conundrum for sure.
 
A throbbing on-off drivetrain vibration can definitely be caused by a bad rear pinion angle, from not having been set quite correctly after installing the SYE and DC driveshaft.

Was the rear pinion angle raised sufficiently that it now points directly up in line with the driveshaft so it points directly at the CV joint? Like this?

CV Driveshaft Angles.gif
 
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A throbbing on-off drivetrain vibration can definitely be caused by a bad rear pinion angle, from not having been set quite correctly after installing the SYE and DC driveshaft.

Was the rear pinion angle raised sufficiently that it now points directly up in line with the driveshaft so it points directly at the CV joint? Like this?

View attachment 74104
Yes, pinion angle is set correctly. I have it sitting 1 degree lower than the driveshaft angle to compensate for the axle rotating upon acceleration.
 
Yes, it could be related to that. Jeep put that balancer on there to dampen something. That is one of the pitfalls of doing an SYE that few of us think about. Sadly, you can't re-install that balancer after the SYE, so it is a conundrum for sure.
Okay, so basically nothing can be done about that?
 
The vibration starts around 55-60 mph and does not change in intensity as the speed increases. It can be felt in the pedals, the seat, the console and steering wheel.
have you cured your vibrations? or are you just living with it?
 
have you cured your vibrations? or are you just living with it?
Just living with it for now. To cold in Michigan to be working in a non heated garage. Hopefully I can start crossing things off the list once the weather breaks.
 
I hear ya man. might be worth checking out the yolk on the end of the SYE. we had a bad terraflex yolk out of the box with my SYE kit recently. we replaced it with a Tom Woods yolk and it was like flipping a switch 100% of the vibes are now gone. worth a shot.
 
I hear ya man. might be worth checking out the yolk on the end of the SYE. we had a bad terraflex yolk out of the box with my SYE kit recently. we replaced it with a Tom Woods yolk and it was like flipping a switch 100% of the vibes are now gone. worth a shot.
Thanks for the advice! I'll have to check it out but how do I go about doing it? Just take it off and look at it or would I have to just buy a new one and see if it fixes it?
 
no way of telling just by looking at it. try a new one from tom woods. let me know if that helps your problem.

Thanks for the advice! I'll have to check it out but how do I go about doing it? Just take it off and look at it or would I have to just buy a new one and see if it fixes it?
n
 
I have a 3.5" suspension lift, a 1" body lift and 1" transfer case drop. My 2004 5 speed TJ has a harmonic balancer on the output shaft of the xfer case. I recently had it re-geared from 3.73 to 4.56 with a Detroit Tru Trac LSD in the Dana 44 rear. I had no vibrations before the re-gear and none now. Many have recommended a SYE along with a CV drive shaft but I'm of the opinion 'if it ain't broke don't fix it'. Until something warrants changing I will stick with what I have. I have followed far too many threads where serious money is spent chasing vibrations and problems still exist.