pinion angle lesson, please

[demulsion]

I'm trying to finalize everything in my head in preparation for finishing my 4wd conversion. One thing I don't know much about, is the importance of pinion angles. Any rules of thumb, basic guidelines, helpful websites, etc. on the matter would be greatly appreciated.


A little background to my question: Because of the trans. that I am using (A833od), my transfer case (NP205) will sit farther back than normal, so I want to make sure I'm not going to put the rear drive shaft in a bind and eat U-joints, or something like that. There is a possibility to move things forward 3" if need be, but I'd rather not spend the extra time and money if I don't have to...

[surfnuke9]

The guy in this link (Billavista) writes just about the best tech writeups on anything you could ever want to know about Dana's, drivelines and 4X4 topics.

http://www.pirate4x4.com/tech/billavist ... ndex2.html

[Lowdown]

If you want the real deal, engineer's explanation, definitely read Bill's write up.
In a nut shell, if you're running drive shafts with single u joints on either end, then you want the pinion angle to match the angle of the output on your t-case when the truck is at ride height.
For instance, if the rear output measures 2* below neutral/level (-2*), then the rear pinion angle must measure +2*. The idea is that the faces of the outputs are parallel which allow the u joints to be nuetral at ride height.
If you're running a CV shaft, then you can point the pinion directly at the t-case output.

[demulsion]

Well, I made it a page and a half through the Pirate article before I developed a headache... Fascinating stuff, thanks for the link. Lowdown, thanks for the nutshell, that's more on my level!

[surfnuke9]

If you ever feel the need to become a 4X4 NERD,.....read ALL of Billavistas stuff. He is one smart, dedicated guy.