I had an issue where my steering shaft was wiggling up, down and side to side, but only by a fraction of an inch. Enough to make the vibration of my warped rotors resonate throughout the dash and make the cab noisy when slowing down from high speeds. Although probably not vital, it was quite annoying.
After changing out my upper steering shaft bearing twice, there was one thing I noticed. The bearing didn't exactly "hug" the shaft, which seemed to be causing the source of the excessive play of the shaft in the column. To cheaply fix this, you could line the inside of the bearing, where it makes contact with the shaft, with a layer of electrical tape. The thickness of the tape is just enough to make the shaft grab the bearing and stay put. However, this is not a permanent fix and may need to be done again in the future due to the tape wearing down.
The only real way to fix this problem is to replace the entire upper steering shaft. The reason being, that the teeth on the shaft which grab onto the bearing become worn down due to age. They should have somewhat of a point, not flat (shown in photo). When sliding the bearing down the shaft, it should stop at the teeth and require pressure to fit the bearing around these teeth by means of a brass drift (lightly tapping around the inside of the bearing) or a section of small pipe which will tap down onto the inside of the bearing. Either way, the bearing should not just slide over the teeth loosely.
I myself am not sure as to what causes the wear on these teeth, be it normal wear and tear or possibly quickly taking a sharp turn or putting to much pressure on the wheel in one direction. If someone knows, I'm sure we would all like to hear of it!
Here's a more permanent, if a bit "ghetto" solution.
Pull the shaft, take a nice, sharp punch & hit the shaft around where the bearing goes. This will displace metal, making ridges. Make 15-20 marks at each bearing location.
We do this a lot at work on shafts that are worn. Especially if we don't have a replacement part. On industrial equipment , running under a continuous load, it usually lasts a few weeks. On a steering shaft, it SHOULD almost last a lifetime.
I ran into a simular issue this summer when I rebuilt the jet pump on my boat. The thrust bearing was to be press on but my shaft was worn enough that it just slid. I was going to knurl it but my machinist said it would distort the shaft enough that he would not recommend it. He turned me on this Loctite, I don't remember the number, that was specially made for shaft bearing. The stuff is super strong once it cures and requires heat to bust it free. I was skeptical at first because this shaft spins 1:1 with the motor so the bearing spins 4-5K rpms when I am on it but it worked just fine. I wish I could remember the number. All I can tell you that it was green. It was a small tube that cost around $5. I know the Napa around here carries it.