I have a sye with. Cv driveshaft an I just boosted my jeep up to about 5 inches of lift. I'm getting serious vibrations in all kinds of scenarios. I used an angle finder on the output shaft of the trans and pinion yoke and subtracted one from the other and I came up with 11 degrees off!
Does that sound reasonable?
Should I use a different angle shim to compensate for when the axles under load?
Where do I even get shims that big?
Please help it's my dd

 

I think mine measured about the same.

When I asked about this, I got comments that I must be measuring wrong but I'm pretty sure I wasn't.

I also have a ax15 with a c8.25 so that may have something to do with it.

I am using 8 degree shims I got from IRO.

Mine are about perfect now that I fixed the shackle angles and the leafs have settled some.

Even that 8s are a little problematic at the lower shock mounts.

 

Yea I'm running the same axle and trans. How did you fix the shackle angles? I'm running brand new re3.5 leafs and stock shackles

 

Use an extended shackle ... Say around 1" or 1.5" lift and that should lessen the need for so much shim angle (it will rotate the pinion up).
Either that or cut and reweld the spring perches.

 

Best I can do is 8 Deg.
http://www.seriousoffroadproducts.co...2.5-X-8-RE1469

Don't forget the pins....
http://www.seriousoffroadproducts.co...NT+CENTER+PINS

 

I have some 1.75 ones I took out cuz I had too much lift maybe I could put them back in and sandbag it

 

Relocation box that adds lift works too

 

Sorry already ordered them from iro, I am interested in your Utk steering upgrade though. How hard is it to ream the knuckles and whatnot? Is there a write up that could help? And where do I get a reamer?

 

For 5" lift, 4 - 6 degree shims should be adequate. Tilt it with 11 degree shims and the pinion bearing will likely starve of oil.
You want close to zero angle at driveshaft/pinion. The double-cardon joint handles the angle difference.

 

If its 11 degrees off you need to divide that in half for to get the best shim value. If you move the pinion up the other half of the shaft comes down an equal amount. I'd put a 6 in it and call it a day

 

I've heard that you want the pinion angle slightly below the driveshaft (like 1 or 2 degrees) to keep the u joint moving and lubricated

 

I used no lift shackle relocators from HD Offroad. These allowed the rear leafs to flex and eventually settle in.

However, I have RC 4.5" rear leafs which have a reputation for being short.

Are your current shackle angles OK?

 

Not really, it's at about 90degrees