measured my driveline angles... now what?

I have an '01 with a 3" lift, factory single cardan driveshaft, and get driveline vibration at 48-50mph. With a 1" transfer case drop my TC centerline points 5 degrees downhill and my pinion points 10 degrees uphill. When the axle wraps, does it point more downhill or uphill? I want 3 degrees of difference, right? So I either need 2 degrees of shim or 8 lol, depending on which way the axle wraps. Also, where should I be measuring the angle on the axle? I picked a couple flat spots and got about 10 degrees but I'm not completely positive any of them are parallel to the centerline. Thanks!

You want the pinion and output shafts parallel. As you accelerate, the axle will rotate clockwise in your picture. Asusming your measurements are good - as you accelerate the pinion angle will increase slightly to maybe 12 or 13 degrees. That gives you a 7 to 8 degree difference. Get a 6 or 8 degree shim and install it with the fat end to the front. This will bring down the pinion angle.

Ok, that's kind of what I was thinking. Does the fact that it needs 6-8 degrees of shim indicate some sort of problem? That seems like a ton.

first, use the back of the center section to get your pinion angle. Get measurement, then remove TC drop, remeasure if needed.

The purpose of the TC drop is to lessen the angle between the driveshaft and TC output, right? What's the maximum recommended angle? I guess if I remove the drop and I'm still under the limit, and the vibes go away then I'm ok, right?

Ukraine Train said:

The purpose of the TC drop is to lessen the angle between the driveshaft and TC output, right? What's the maximum recommended angle? I guess if I remove the drop and I'm still under the limit, and the vibes go away then I'm ok, right?

Click to expand...

Equal and opposite. Max operating angle on a u-joint is about 6 degrees. But you don't want to run it there as it will wear quickly.

Measure, then correct.
http://www.naxja.org/forum/showthread.php?p=243629744#post243629744

Once you have the angles correct, all will be fine in the world and there will be whirrled peas.

Ron