Rear driveshaft vibration
12-08-2010, 01:19 PM
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Rear driveshaft vibration
Ive got an 07 2dr sahara with a 4in lift and no adjustable control arms yet. Ive gotten a local driveline shop to make new driveshafts for me, but after installing the rear driveshaft im getting some speed specific vibration. Front driveshaft has been removed at this point. Its a double cardin style shaft and obviously the pinion angle has not been adjusted.
I can feel a wobble when starting from stop, and a high frequency vibration at 40km/h and 55km/h.
The driveline shop is having difficulty eliminating the problem and at the moment is telling me that its most likely due to a 3/4" offset horizontally from the tcase to the diff. To me this doesnt seem likely. They say it has to do with the "phase" of the ujoint or something. They say when they adjust the phase it changes where the vibration comes in, and theyre trying to find a sweet spot. To me this isnt acceptable. If it vibrates, theres something else wrong.
So what are some probable causes and what are the specifics to building a rear driveshaft for a 2dr with 4" lift?
Thanks in advance!
I can feel a wobble when starting from stop, and a high frequency vibration at 40km/h and 55km/h.
The driveline shop is having difficulty eliminating the problem and at the moment is telling me that its most likely due to a 3/4" offset horizontally from the tcase to the diff. To me this doesnt seem likely. They say it has to do with the "phase" of the ujoint or something. They say when they adjust the phase it changes where the vibration comes in, and theyre trying to find a sweet spot. To me this isnt acceptable. If it vibrates, theres something else wrong.
So what are some probable causes and what are the specifics to building a rear driveshaft for a 2dr with 4" lift?
Thanks in advance!
12-08-2010, 01:37 PM
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Did they swap out the flanges? Or rig up some kind of adapter plate? If you have new flanges, you can't put the stocker shaft back in... 
Spend a few minutes out on Tom Woods website. Plenty of info and graphs and pics to explain what is going on.
CV Shaft:
Stock Shaft:
As mentioned above, you will need adj uppers to set the proper angle.
And no adj trackbars to center the axles either, I take it?
Spend a few minutes out on Tom Woods website. Plenty of info and graphs and pics to explain what is going on.
CV Shaft:
Stock Shaft:
As mentioned above, you will need adj uppers to set the proper angle.
telling me that its most likely due to a 3/4" offset horizontally from the tcase to the diff.
Last edited by nthinuf; 12-08-2010 at 02:04 PM.
12-08-2010, 01:45 PM
#6
12-08-2010, 02:07 PM
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Looks like ive got an unexpected xmas present coming my way! I guess I'll be upgrading to the 4" FT short arm system sooner than I thought. Ive had about enough of this cheapo RC lift anyways haha!