I don't see the problem. The car runs straight and steers as it should. So I assume the alignment is done correct. If you replace the steeringwheel on the splined shaft a few teeth, you don't mess with the alignment or steeringbox I guess ?
The "problem" is the "dead spline" or "master spline" in the steering column AND the steering wheel. This these two components get assembled ONE WAY at the factory and later. Otherwise, one misadjustment of the steering linkage could result in other mis-assembly actions that would be difficult to diagnose later in the vehicle's life, should they be disturbed.
The steering gear needs to be "dead center", with the pitman and idler arms being parallel to the front/rear centerline of the vehicle, long-ways. I would say "parallel to the driveshaft", but that item usually has a bit of an angle to it between the end of the transmission and the front of the rear axle yoke.
From there, the tie rod linkage adjustments would need to be even, side-to-side. The noted spline on the end of the steering column (top side) would also need to be at "12:00 0'clock" when all of that is assembled, so the steering wheel would be "straight".
I tried the tie rod end adjustment once and it got to be more involved than just letting the steering wheel be a bit "off-center". I didn't drive the car, just let it sit still as I did these things. LOTS of getting up and down, off the ground, checking and re-checking things. Got it off, then back where it was originally. BEST done on an alignment machine!
Now, front end alignment is nothing more than "lines and angles", plain and simple. Just MANY of them and knowing how it all interacts. There ARE several kits to do this on your garage floor (or any other "flat" surface, just that things need to be flatter than just by the eyeball, like on an drive-on alignment rack). Will need a calibrated bubble level for the caster and camber measurements, though. Seems like the kits are a few hundred dollars? So two alignments would pay for it, BUT how often to you need two alignments on a vehicle? OR you're willing to spend the time to do it yourself? ONCE you find a good shop to do these things? The electronic alignment machines do all of this electronically AND to tighter tolerances than might otherwise be possible, by observation.
The KEY thing is to have the vehicle at "road load conditions". Even in the "old days", the alleged best alignments were done with the driver's weight simulated in the driver's seat. Or any additional passenger weight compensated for with "weight bags". The desire was to set the factory specs with the car loaded as it would be driven down the street. Not sure if that really mattered as all of the alignments we have had done were done "empty". The amount of gas in the gas tank can even allegedly make a difference!
Plus the is a special tool to move the tie rod end sleeves with, too. "Pliers" can work, but are not as accurate, by observation and might deform the sleeve in the process.
As for "not wanting to pay for a full alignment", there is a certain amount of time and labor involved in getting the measuring fixtures assembled onto the vehicle, just to make a toe-in check, that you might a s well get the whole deal done. In other words, the costs would be basically the same, either way. BUT be sure to tell them you only want a toe-in check and steering wheel "centering". The OTHER thing is that something "might have moved", which made the previously centered steering wheel now off-center. Doing the full alignment should find that, if it has happened.
SO, consider the crown/slope of the roads you're travelling on when you notice the off-center orientation of the steering wheel. Check it on other roads, not just one, for good measure. Hopefully Interstate highways or similar.
ALSO consider that due to the steering gear's gear ratio, what might be a "big difference" in steering wheel orientation will result in .5 degree of actual wheel movement, or less. The newer GM pickups have an "off road" graphic available on their Driver Information screens (tilt sideways, tilt front/rear, steering wheel angle). To get to where the front wheels are actually turned 1 degree from center, the outer ring of the steering wheel will need to move more than 1" from center. Getting a steering wheel that far off-center in a wheel alignment is NOT that common, by observation.
Might it also be that the steering gear lash adjustment need some attention, too?
Enjoy!
CBODY67
