As seen on all forums the factory driveshaft didnt last very long. Replaced with Rubicon Express shaft but cant get the vibration out, used cam bolts, turned up and back down, cant get it to stop. Have a 4" lift, does the shaft need to be staight with the pinion, if so worried about pinion bearing not getting oiled good. Advice please!!!!!!!!!!

 

Adjustable control arms are the way to go for adjusting pinion angle. I got upper and lower rears and that corrected mine perfectly. I am assuming you are having vibration issues with the rear ds?

 

For the rear your shaft should be straight with the pinion. The front is a compromise between pinion angle and Castor.

Review the front end allignment and lift installation write-ups in the write-up section for how to do this.

 

Yeah it the rear, but does the ds need to be pretty much straight with the pinion, and will the pinion bearing still get oil?

 

Yup, the rear needs to be straight. I can't address the oiling issue as I don't know enough about that.

I do know that there have been several threads address that issue and I don't recall it being an issue.

 

This is my first real problem with this Jeep. Thanks for the help guys!

 

When you changed drive shafts, did you make any adjustments? In other words, before the factory drive shaft failed, was it vibrating? If not, and the drive shaft was ALL you changed and THEN you got the vibration, then it is clear that the new drive shaft is the culprit. If that's so, no amount of adjusting pinion angle will cure it, because the drive shaft is at fault.

 

It may/may not apply here, but some of the guys in the Mustang camp had some issues with some aftermarket driveshafts that would have vibration issues. Some of them were able to correct this by reattaching their driveshaft at a 90 degree angle until it fixed the vibration. Other than that...pinion angle.

 

The stock shaft has the CV joint which allows there to be angle between the driveshaft and pinion.

Most aftermarket shafts are double cardan which are stronger and allow a bit more angle, but the pinion must be aligned with the driveshaft. Otherwise you get vibrations.

 

Go out to Tom Woods website. They have pics/diagrams/explanations of the angles with the different driveshaft types.