New shaft is required. Those tiny u-joints are not serviceable...they are pressed-in and then peened to hold them in place. I cannot recall if the upper shaft can be swapped with the column in place...seem like I did that once. It was a total wrestling match, and it might be easier to pull the column out to swap it. Column removal is not a big deal but, you're ratchet strap will have to go. GM sells a small tool called a "anti-rotation pin" that gets inserted into a hole on the underside of the column. This is nice because it stays with the column the entire time, to keep it from rotating. Here's a pic from the GM manual...
View attachment Hummer-H3-Steering-Wheel-Column.pdf
These are $12 on Amazon.
Failure to lock the column can cause damage to other "stuff". Inside the turn-signal mechanism there is a ribbon cable that connects the horn, air-bag, cruise control, and turn signals, to the truck's BCM. It is only long enough to accommodate 3.5 turns of rotation, lock-to-lock. So if the wheel gets "spun"...the ribbon snaps and the entire module is junk. Additionally, there is a yaw sensor at the base of the column that tells the computer the angle of the wheel....its basically a tiny reluctor ring (like an ABS sensor). This sensor is calibrated to "center" when it gets installed, and it must not be rotated while working on the steering. If it gets out of calibration...the computer will think your steering wheel is not centered, and you'll get a Stabilitrac warning light. Its a PITA to fix. So...by any and all means...keep the steering column locked whenever you are working on it.
