Can someone do some driveline math for me?

[trav0302]

I need to move my perches so as i am doing that i might as well set my angle too. Here are some pics i took hope there good enough. I will post the angle that i wrote down with the pics. Long story short I don't trust my own math on this and i dont want to F it up. So can someone help me find the angle to set my axle at?

back shaft 20

front shaft 21

here is some that i wasn't sure were needed

 

[imiceman44]

Well the ones you thought are not needed are the ones you need to get.
The angle you got was on the driveshaft on both ends, if it was didfferent it would only mean your driveshaft is bent.
What you need to have is the angle at the axle yoke which looks like 10 degrees, and the angle at the tcase output, which I couldn't read.
You want to have them equal in theory, but since the axle will turn up when torque is applied you can add 3 degrees to compensate.
I know someone else will post a pic and more detail so you can understand it better.

 

[trav0302]

This is what a buddy told me after looking at the pics.

So transfer case is 10* down.
Drive line is 20* down.
That means s the difference is 10*.
You want the angle of the pinion and the drive line to be slightly higher to compensate for rotation of the axle due to spring wrap, 12*.
So the answer I think your looking for is 8* for the pinion.

 

[imiceman44]

This is what a buddy told me after looking at the pics.

So transfer case is 10* down.
Drive line is 20* down.
That means s the difference is 10*.
You want the angle of the pinion and the drive line to be slightly higher to compensate for rotation of the axle due to spring wrap, 12*.
So the answer I think your looking for is 8* for the pinion.

The pinion will rotate up, so imagine it up 2-3 degrees and match the tcase output to that.
so you want to pint the pinion down 2 degrees from where it's equal to the tcase angle.

 

[owenst7]

I would like to point out that the 14 bolt yokes are not square on the sides, so taking an angle measurement there is not very accurate. The best place I've come up with that is also easy to read is the sealing surface under the diff cover. It is perpendicular to the pinion, so you can transfer the angle of that surface to a pinion angle by rotating 90*. I think you could also use the web on the side of the casting along the pinion, but it's not very big and usually hard to read while you're under the truck.

Hopefully that makes sense. I'm not very good at putting these things in words.