New Leaf Springs to adjust driveline angles

Hello all-

I had noticed a vibration around 50mph a little while ago, and after investigation I saw a torn carrier bearing. I replaced that, greased the zerks and was hoping that was that.

There is now a new vibration that happens around 40mph. I have gone deep into the driveline angle issues, and have measured my angles to be:

Transfer Case output angle : 2.6 degrees
Front Prop Shaft: 2.3 degrees
Rear Prop Shaft: 9.2 degrees
Pinion angle: 2.1 degrees

which means I have working angles of:
0.3 for the ujoint at the transfer case
6.9 for the ujoints at the DC linkage
7.1 for the ujoint at the pinion

I feel like the vibration is coming from the pinion connection. I have also noticed that my leaf springs are quite shot (I think), and was planning on installing new ones. I have a topper, a drawer system, and have a little bit of gear in there for most of the time, so I was going to go with the General Springs HD springs.

I was wondering how replacing the leaf springs will affect the driveshaft angles, and if I will need to do more to fix the vibrations, or if anyone had any suggestions! Thanks!

 

Your drive line angles aren't going to be a problem unless you've got a ton of lift, which it doesn't appear so.

Your vibration is far more likely related to a bad u joint, brake drums, wheel bearings, or pnion/diff bearings, in that order. Wheels and tires could be a factor as well, get them road force balanced.

 

^what he said. Normally new leaf packs would not affect your drive shaft angles at all, but your stock leafs are so worn out that new packs will probably improve the vibrations if nothing else.

As it is, your angles are nearly cancelled (with correct sign): -6.9 degrees at the double cardan and +7.1 degrees at the pinion is almost perfect (with a double cardan joint you want the pinion pointed right at the center bearing, minus a couple tenths to account for driveline lift during acceleration). So you’re in good shape there.

My money is on a bad u joint at the rear pinion.