2008 Unlimited Rubi, Auto, 513s, 35s TeraFlex 3".
Had Teraflex 3" installed (at a shop) and ended up with close to 5" of lift. Immediatley after lift experienced vibration. Replaced front DS with TeraFlex. Reduced vibration about 50%. Installed TeraFlex rear DS. Vibration worse than in the beginning. The vibration is one you can hear and feel. Have had lift re-torqued, tires renbalanced twice, drive shaft balance checked, etc. Vibratiions start at 45 and increase with speed. Have put 4K miles so lift should have settled by now. Shop's nexts step is to look at the gears. Any suggestions? Thanks.

 

you probably have too much caster. bring it back to something closer to stock. if you still have vibes after that, you might want to have your ds rebalanced.

 

I would assume that any reputable shop would have done this but I have to ask...is the pinon angle set correctly? If so, then try having a professional alignment done.

 

agreed 100%. if the vibes got worse after installing your rear shaft, the pinion angle is probably off by a bit. you might want to give that a look as well.

 

Do you have asjustable control arms on your JK?

 

Yes it has adjustable control arms and it has been aligned.

 

an alignment will not effect driveline vibrations. too much caster, a pinion angle that is off OR a drive shaft that isn't perfectly balanced will. now that you are running 5.13's, your front ds will be spinning really really fast and any imperfection will translate into vibes. reducing the amount of caster you have will help. in the rear, you need to make sure that the ds and the pinion are parallel. if they are off, you will have vibes.

 

They removed the rear ds and drove it and there was no vibration so it has been isolated to a rear problem. They also said the pinon angle was correct. They also took the ds and had the balance checked and all was ok. Evidently somthing is still not right since it still has a vibration that you feel and hear. Appreciate the comments and help. Pretty frustrating experience.

 

It's either one or the other, pinion angle, or balance. If it's not balance, one of the control arms may be adjusted more than the other, or tweaked so to speak, they may have to play with the angle abit.

 

think about this for a sec... they took off the driveshaft and "there was no vibration". IF the pinion angle really is correct, the problem IS with the drive shaft itself. i realize they say they "had the balance checked" but i hardly believe all was "ok". i would take it to a real driveline shop and have it rebalanced. should only cost like $40 to do. IF something else were the cause of your vibes, you should still feel it even with the drive shaft off.