Spring perch rotation (angle) for a CV Drive shaft?

I'm switching to a rear cv drive shaft, also putting on new 4" lift springs and using an axle that currently has no spring perches on it. So I'm contemplating what rotation to set the spring perches at. The new springs came with large shims (like 8 degrees or so), but to me it seems like I should just take them off the springs and set my spring perches accordingly, since I'm welding on new perches anyway. The shims will only serve to lower the vehicle by the thickness of the shim (over 1/2").

Then, if I find that I need to adjust my pinion angle slightly after it's all done, I could add a thin shim (1 or 2 degrees). Am I correct in this line of thinking? Thanks.

 

That is what I would do (cut the perches and replace). From what I recall you should point the nose of the rear right at the end of the CV on the transfer case. Or down just a tad to allow for a little axle wrap under power?

 

I was planning on pointing the pinion about an inch below the transfer case yoke. First time for me on a lot of this stuff, so I figure it's best to ask.

 

here's some good info. http://www.4xshaft.com/index.html

more here. http://www.pirate4x4.com/tech/billavista/PR-shaft/index.html

 

Thanks for the links Mike. The one unknown for me is the amount of pinion twist or axle wrap I should allow for when setting the perch angle. It's relative to my rig I know, so here's my set up in case someone else has something similar and can help me get dialed in.
I'm running a v6 with 4" leaf spring lift. It's strictly a trail Jeep that will see little to no street use.
Thanks.

 

Get an inexpensive angle finder from HF, Sears, etc. With a CV joint driveshaft I've found 1-2 degrees below the transfer case works quite well. YMMV,etc. Nickmil

 

Ditto. Lose the shims, go two degrees down. Set it with all of your normal weight (spare tire, tools, seat etc) at lest thrown in the back of the jeep.

 

i set my pinion facing higher than where the driveshaft is pointed. So that the angles are almost both the same. then i made a ladder bar to take care of the axle wrap. works great

 

Not sure I understand that one, but a ladder bar is not an option for me since I don't want to limit articulation. I'm really not worried about axle wrap, just noting that some will exist and the angle of the pinion needs to accommodate that as described by the guys in the previous posts.

Thanks all!

 

what i mean is that rather than point the driveshaft straight out from the diff i tilted the pinion upward so that the angles on both the tranny and the diff are similar rather than the tranny having angle and the diff end relatively straight. However i did a spring over on mine so it ended up being somthing like 6 inches of lift so i needed the extra angle on my shafts which are the stock style joints

 

Gotcha. When I read the earlier post it sounded like you tilted the pinion up to point higher than the transfer case, but I know what you mean. Thanks.