@Doubeleive Are you using inner clips on the U joint, the ones under the yoke?
Did you tap the yoke with a hammer to make sure the joint was seated and free to move?
I had an issue recently where I had to use a thinner clip on the front shaft after a U joint change....couldn't get it to free up as much as needed.
I also had a driveline shop near me totally screw up both my driveshafts and I'm replacing both with 2 new shafts from the Driveshaft Store...cut my losses.
Did you tap the yoke with a hammer to make sure the joint was seated and free to move?
I had an issue recently where I had to use a thinner clip on the front shaft after a U joint change....couldn't get it to free up as much as needed.
I also had a driveline shop near me totally screw up both my driveshafts and I'm replacing both with 2 new shafts from the Driveshaft Store...cut my losses.