Alright...bumping this one back to the top instead of creating a new thread!

operating angle--the angle between the drive shaft to transmission and drive shaft to pinion, yes?

so, I want to set my operating angle first, THEN set my pinion angle?

or should I totally ignore operating angle and just make sure trans and pinion are parallel?

what is the preferred operating angle? isn't there a number that is preferred so that it promotes the needle bearings to rotate?

I can set this by shimming the trans shaft up or down, right?

THEN, once I have the operating angle, I set the pinion angle to be parallel to the transmission? or I set it to be 4-5 degrees nose down from the transmission?

WHY IS THIS SO CONFUSING?!?! I've read several times that you want to set the pinion to be parallel to the trans, THEN rotate the pinion down 4-5 degrees...WHY!? THEN IT'S NOT PARALLEL!

I realize axle wrap under acceleration will bring it back into being parallel, but I'm trying to chase down my vibration that is constant at certain speeds. it vibrates under acceleration, cruising, AND deceleration.

one place I read that if it vibrates on acceleration, to rotate it pinion down, and if it vibrates on deceleration, to rotate it pinion up.

what about when it always vibrates?

with the truck on jack stands, my transmission center line is about 2 degrees off from my pinion center line, so my angles definitely need adjustment...but do I set the pinion to be parallel to the trans NOW, or do I set it to be 4-5 degrees nose down from the trans? if I go nose down, won't that make my truck vibrate when cruising under light load and when slowing down?