From the FAQ's
Make sure the movement of the new rack is centered left to right when installing the U-joint. The last paragraph first sentence is important.

Dan



"Replacing the Steering Shaft U-Joints. [Bruce Young/Herb Goltz] Disconnect the battery ground to deactivate the air bag and center the steering wheel. Jack up the front of the car and remove the belly pan. Remove the retaining spring clip (if there is one) from both upper and lower U-joint bolts, remove the nut and tap the bolt out, then drive a machine screw into the space between the joint halves to spread it out to make it easier to remove. If you've had to move the steering wheel to gain access to the bolts, return it to the center position. With BOTH u-joints sufficiently loosened — per screw method, plus wire brushing and oiling shaft splines — the shaft is moved (maybe "driven") upward to free the lower joint, then swung aside and moved down to free the upper joint. You may need a hammer or air impact hammer to move the lower joint and shaft upwards. Then the shaft and both joints are free to do whatever is needed at the bench.

NOTE that each joint fits the shaft in only one position. Pay attention to steering wheel orientation when shaft is separated and removed to aid in reinstalling."