I'm posting this because of all the different and unique ways I've found on the internet for pinion angle adjustment, some of which can be very confusing.

I started by lowering my car with a set of Eibach to find out that driveshaft allignment and pinion angles are greatly affected. An adjustable panhard bar took care of the centering issue. An adjustable torque arm took care of the pinion angle issue.

To start the pinion angle adjustment, I threw all the crazy math problems away that I found on line.
1. Place car on jack stands, making sure the full weight of the car is resting on the stands.
2. Measure the angle of your transmission shaft. The easiest way is to place your magnetic angle finder across the u-joint cap. Make sure to place it on a cap that is on the yoke, not the shaft. You can also take a reading at your harmonic balancer. This would be a verticle reading, so you would have to add or subtract 90 degrees, depending on how your viewing the gauge. I used the u-joint cap, and read it looking in from the drivers side. My reading was 3 degrees, to the left of 0.
3. Move your gauge to the rear. Place it under the flat part of the adjustable torque arm plate and look at your reading, again from the drivers side. Adjust it to the exact same reading as the trans measurement, then adjust the nose of the rear downward 1 more degree.

Thats it! Done!

No need to worry what is negative, what is positive and all working u-joint angles fell right into place!

Hope I explained this right

 

I recently swapped my rear and put on smaller springs than my stock ones. i now get a vibration noise at 70. could my pinion angle have been affected? Thanks for this. I will try it out.

 

Yes, it could be. There is a chance the vibration could be from the new rear. I would start by making sure the angles are correct. If you have any problems or questions, feel free to message me.