You're probably not doing it right. You mark the joint how it goes together, and only then take it apart.

When you put it back together make sure you align the grease nipple hump with the dip in the flange if you're using that type of joint.

Put the UJ inside the two eyes. Then move it to one side so it sticks out of the eye and fit the bearing cap to it. Then put that cup in its eye using the joint to keep the needles in place. Press the eye too far in so the joint starts poking out of the other eye. If you press it right through youre in BIG trouble though. Put its circlip in at this point cos it's easy. Then fit the bearing cup over the pokey out joint and press it in place.

Do the same for the other half of the joint.

Finally bash the joint with a leather hammer to seat the joint cups nice and tight against the circlips (no binding).

Ten minutes tops to change a U joint with a bit of practice.

Regards

Pete